Petrotech Journal June 2009

Journal of thePETROTECHSociety

PETROTECH 2009“Underground Coal Gasification:

Vital Technology for India”

“Prediction of Crude Blend Compatibility - way to enlarge

the Crude Processing Slate”

R&D ISSUE

Journal of thePetrotech Society

June 2009

Volume VNo. 4

Esteemed Patrons,

Our momentous biennial event of PETROTECH 2009 from 11th – 15th January 2009 has just gone by. Rightly so, the

previous issue was dedicated to The 8th International Oil & Gas Conference and Exhibition. The commemorative

issue was formally released by Dr. Indira Samarasekera, President, University of Alberta, Canada during inauguration

of prestigious parallel track event of ‘Academia Industry Interface’ and was later distributed widely amongst all

the participants of the Conference. Likewise, as a sequel to ‘R&D Conclave- III’ held at Goa from 5th-7th March

2009, this issue is being brought out as R&D Issue with focus on research activities currently being pursued both

in upstream and downstream sectors. The issue also focuses on best posters which were selected amongst over

400 posters and awarded 1st & 2nd prize during the Conference. It is hoped that such exposure to new research

ideas can help in terms of possibilities for further follow up and research on the poster subjects by interested

scholars. Special coverage has also been given to variety of technical papers for appreciation of the readers who

can reach out for further details at our website which includes an e-library. Our e-library is fully functional and is

being visited by readers almost every day, total hits so far having crossed more than 1200.

Petrotech Society is committed to knowledge dissemination and has facilitated first hand appreciation of Industry

Awareness by students/faculty through visits of industry experts to various universities & institutes. This has

got a very wide and welcome response from the student community as all such expert’s lectures by industry

executives have been very well attended at all our chapter locations. Furthermore, the Society organized a first

ever Industry Educational visit to advanced industries in Canada under the MoU signed between Petrotech Society

and University of Alberta. This year a similar visit will take place; a batch of 18 senior executives from industry is

visiting the University of Alberta, Edmonton in order to get exposure to new and latest technology updates. We

sincerely hope that such visits cannot only be useful from a knowledge sharing point of view but also rewarding

in several ways to the visiting team members.

The Society completed 10 years of its glorious events on 8th June 2009. A befitting function was organized on 9th

June 2009 in which many veterans and doyens of the industry participated. Chairman of the Society honoured all

past Chairman, Presidents and Secretary General on this occasion. It was decided to constitute a Veterans Group

which can meet periodically to discuss the latest advances and related subjects as well as current multidimensional

energy issues both in upstream and downstream sectors. The society has thus travelled a long way from its

earlier formative days making all round progress and reaching out to working executives and academia across

the country by partnering with various corporates in organizing annual schools and seminars in different regions

of the country. You would all be glad to know that initial preparations have already begun for the next biennial

event. This time ONGC is the host corporate and CMD, ONGC is personally monitoring all activities to ensure that

newer standards are set during that event. It is sincerely hoped that with your continued patronage Petrotech

Society will attain greater heights in the years to come.

With best wishes,

J L RainaSecretary General & CEO

Editorial

Journal of the petrotech society

C O N T E N T SJu ne 2009

Foreword 5

Underground Coal Gasification: Vital Technology for India 6Dr D M Kale

Dynamic Optimization of Motor Spirit Plant 10Dipak Chakravarty, Dhananjoy Ghosh, Rupam Sarmah

Smart cementing solutions for wells with low bottom hole circulating temperatures 15Satinath Banerjee and Debashish Dasgupta

Towards a Deeper Solution 21Naresh Kumar

Prediction of Crude Blend Compatibility- way to enlarge the Crude Processing Slate 24Vivek Rathore, Tushar S Thorat, P V C Rao and N V Choudary

Sustainability and Sustainability Reporting 30Satish Chand and Shantanu Dasgupta

Petrotech-2009 34Abstract of Award Winning Posters

Exploration model and hydrocarbon prospectivity of Middle Miocene S1 clastics 36(Tapti Formation) in Heera-Panna-Bassein Sector, Bombay Offshore Basin, India (A new play in known basin)Dhruvendra Singh, Dr. Bamdeo Tripathi, Dr.A.M.Chitrao, A.A.Sheikh K.G.Vijaylaxmi,Santanu Mukherjee,

S.Bhowmick, Rajiv Verma and P.K.Bhowmick

Hydrogen production by direct decomposition of methane 42over supported Ni- catalysts K K Pant, Ashok Chejara and R P Verma

Surfactant based gel: a clean hydraulic fracturing fluid 45Keka Ojha, Ajay Mandal and V Reddy

Basics of bridging particle size selection – no more fine, medium, or coarse 49Robert P. Schlemmer, Yon Azwa Sazali

R&D Conclave III 51Seminar on “Advances in Value Chain of Hydrocarbon Sector” 524th Summer School on Petroleum Refining & Petrochemicals 53Founder's Day 54Summer School in Tribology 56

Editorial Board

J L RainaEditor

Secretary General & CEO,

PETROTECH Society

G SarpalSecretary

Suman GuptaManager

The views expressed by the authors are their

own, and do not neccessarily represent that

of the Petrotech Society.

Printed and published byPetrotech Society at Core 8, Scope Complex,

3rd Floor, New Delhi - 110 003 India

Foreword

Dear Colleagues,

It gives me immense pleasure to place before you the June’09 issue of

PETROTECH Journal.

PETROTECH Society recently completed a decade, a milestone in an

institution’s history. With ten years of experience behind us, we felt

confident in launching a new platform to harness the collective knowledge

and experience of petroleum sector veterans. Christened ‘Petrotech

Veterans Forum’, this platform proposes to bring out the vast knowledge,

professional acumen and managerial expertise of our former business

leaders and policy makers to precipitate a structured brainstorming

experience of envisioning the future of the sector. Realizing that customized analysis and research would be

a pre-requisite, the Society envisages to engage a ‘Knowledge Partner’ to interface with this Forum so that

the outcome is based on factual information and structured prognostication tools and economic models.

We are confident that this initiative will enable significant contribution to our policy makers envisioning

energy security for the nation.

PETROTECH Journal brings to you the latest developments in the realm of petroleum technology.

Technology advancements are an amalgamation of developments in diverse fields, seemingly quite

unrelated to petroleum. How advancements in silicon and wind-turbine technology and micro-biology

and nano-technology impact our industry is a case in point. This journal seeks to bring to you the current

information from across our business value chain.

A Journal is only as good as its content. We are grateful to the authors who have enriched our resource

pool by sharing their expertise with us through this journal. We look forward to your continued patronage

and appeal to our colleagues from the industry to share cutting-edge research, technology advancements

and experiential learning in adapting new technology with the readers of PETROTECH Journal.

Happy reading…

R S SharmaChairman, Petrotech Society

Background

The Indian economy is growing at unprecedented rate of 9% + over last few years. It is necessary to sustain this rate of growth for coming two decades to abolish poverty totally. To fuel the growth it is necessary to have energy. To address this vital issue, the Prime Minister had directed that the planning commission should consti-tute an expert committee to undertake comprehensive review and to make recommendation for policy.

Accordingly, the expert committee has come out with a comprehensive docu-ment in the form of a report “Integrated Energy Policy” (IEP). According to the report India currently uses 16 quads of commercial energy and 6 quads of non commercial energy. To maintain 9% growth rate the commercial energy requirement will be 74 quads and non commercial energy use will be about 8 quads. As of today, percentage share coal in the commercial energy mix is 51.07%. It is expected to retain this dominating position at 50.58%. That translates to 37 quads or 930Mtoe.

The office of the Principal Scientific Advisor to the Government o India has commissioned the study or preparing The National Energy Map for India (NEMI). The study has been carried out by TERI. This work takes into account the various technological options available. The study with the help of MARKAL model has built vari-ous scenarios. Interestingly, the report takes into account the non energy demand of coal in other sectors as

Underground Coal Gasification: Vital Technology for IndiaDr D M KaleONGC

well. The overall finding is similar to the IEP. Under various scenarios the coal requirement varies from 767Mtoe to 2008Mtoe. We need to note that NEMI considers different scenarios and all the important sectors of coal utilization like Industry (process heating), Industry (captive power production), power and ore reduction.

Projected Coal requirement

NEMI considers different growth rates of economy. The low growth rate cor-responds to 6.7%, while Business as usual case considers 8% growth. The growth rate is the case with 10% growth. Energy use and energy mix are also important for projecting the demand for coal. With the advanced already proven technologies there is a great scope or using the energy more efficiently and achieving higher growth with the given energy input. In the energy source options higher nuclear energy capacity is one option considered the other being aggressive renewable energy scenario.

Under all scenarios coal retains the dominant position of supplying more than half of the commercial energy. The table 1 (Ref: no 5.19 NEMI) below summarizes projected coal consump-tion in different sectors and different assumptions.

Other important aspect of coal sup-ply that the report brings out is heavy import dependency of coal. Figure 1 (Ref: Figure 5.37 NEMI). Similar is the case of petroleum import dependency. There are two crucial assumptions. The

Table 1: Coal consumption in various end-use sectors in 2031 (in Mtoe)

Sector BAU HYB HG HHYBIndustry (process Heat) 285 146 490 253Industry (Captive power) 91 106 139 160Power 663 296 1148 581Ore Reduction 137 219 231 370Total 1176 767 2009 1364

Dr. D.M. Kale, Director General – ONGC Energy Centre, holds a Doctorate Degree in Astrophysics from prestigious

Tata Institute of Fundamental Research.

He has more than 26 years of experience in Reservoir Management of Oil & Gas fields and began his career in ONGC in developing Numerical Reservoir Simulators. Later on he established the computer centre and simulation group in the Institute of Reservoir Studies.

As a talented Scientist he has conceptualized several schemes for enhanced oil recovery besides carrying out responsibilities such as heading Exploration Business Group of Eastern Region and Mumbai Region of ONGC. As Head of COIN, Dr. Kale coordinated all the R&D works in Institutes of ONGC.

He superannuated from ONGC as Executive Director (R&D), Chief Energy Centre in July 2008 & subsequently has taken over as Director General of ONGC Energy Centre at Delhi. He has taken initiative in setting up the “ONGC Energy Centre” for Research, Development & Demonstration of all Alternate forms of energy.

He is recipient of the medal of “Peter the Great” by Russian Academy of Natural Sciences.

6 Ju ne 2009


first one is about the projected world production scenes of oil and coal. It is assumed that the world production capacity will expand to meet the ever increasing demand and the prices will be affordable to India. In case of oil and coal the prices have gone up steeply over last five years. In case of oil there appears the supply constraint due to geological, geo political and logistic reasons.

Thus we see that sustaining growth rate of economy with adequate energy sup-ply is a big challenge and coal has to play increasingly greater role in meeting the demand.

The Environmental Issues

The recent scientific findings and think-ing has converged onto conclusion that global warming and subsequent sudden undesirable deadly climate changes are taking place at unprec-edented rate In short recorded human history. As well in geological records it has no parallel. The anthropogenic emissions positively contribute towards warming. The concentration of CO2 in the atmosphere has risen from 280ppm before the industrial revolution to cur-rent value of 380ppm. From 1958, Prof. C.D. Keelings has kept daily record at Mauna Loa Laboratory and since then CO2 concentration in the atmosphere has risen from 315ppm to current 380+. With the world adding 27 billion ton of CO2 every year, the yearly rise is close to 2ppm. It is thought by the scientists that 450ppm is the threshold, and the

tipping point. Beyond this point no hu-man action how so ever extreme has any chance of averting the run away warming and its consequences. The very human existence might be at risk according to Dr. RK Pachauri and his team. Incidentally the team of scien-tists of IFCC (Intergovernmental panel on climate change) was declared as recipient of Nobel Prize for peace. On this background, it is very difficult, nay impossible, to plan the future energy policy without regards to the environ-mental consequences.

Fossil fuel burning is the main reason of anthropogenic CO2 generation. In the years to come strict international regu-lations as well as self restrictions from each nation will make it mandatory to employ clean, environmentally benign technologies or energy generation.

Thus in addition to supply constraint on import of fossil fuels, the environmental considerations require that India must think of : Expanding the resource base and use of fuel (Coal) available indig-enously and using it in environmentally clean manner to generate energy as well as other industrial uses including feed stock for fertilizers and petro-chemicals.

UCG and India

Importing and adopting UCG technol-ogy in tandem with CSS offers a unique opportunity to meet this challenge. There are large known coal and lignite

resources which are too deep to mine. The exploration of such deeper coal resources is far from complete. The oil companies have come across such deposits while exploring for hydrocar-bons. ONGC has discovered estimated 120 billion tons of coal in Gujarat alone. Further theoretically it is known that the high ash content of Indian coal is not an impediment in application of UCG. On the contrary anthracite poses problems in the UCG application due to liquefaction obstructing the necessary permeability development.

UCG & Global Scene

The discovery of huge natural gas reserves in Russia and similarly avail-ability of cheap natural gas in US has discouraged and delayed further devel-opment and spread of this technology for sourcing the energy in the form syn gas from the known large coal reserves in Russia and US.

Initially the development of UCG began in 1920’s in USSR. By 1960’s there were several commercial UCG station in the erstwhile USSR. Today there are operation UCG stations in Uzbekistan (Angren) and in Siberia. With finitude o oil and gas becoming obvious and domestic production of both peaking in US, there has been renewed inter-est in UCG in US. Particularly after oil price shocks the developments have accelerated. Under the leadership of National Livermore Laboratory, 40 odd successful UCG experiments have been carried out at various sites in US. In Europe there is a renewed interest in UK. Pilot tests have been conducted in France, Spain and Belgium.

Australia is very rich in coal resources. There has been a successful UCG experi-ment in Chinchilla and a power plant is expected to start power generation soon. South Africa also has coal resources. Now for years CTL technology has been commercialized in South Africa. Sasol through CTL satisfy substantial liquid hydrocarbon requirement of South Africa (About 12million tons per annum). Coal Gasification is the first step of CTL the second being Fischer Tropsch reaction. Naturally there is a great interest in UCG in SA and recently a pilot has begun suc-cessfully at Majuba.

Figure 1: Import dependency of non-coking coal across various scenarios in 2011 and 2031

Ju ne 2009 7


Large number of projects especially in abandoned coal mines has been reported from China too.

UCG Technology and Upstream Hydrocarbon Industry

In UCG a reaction chamber is formed in the coal seam itself. Through a well drilled in the coal seam oxidant and steam is injected after initially igniting the coal. Figure 2. The resultant gas-eous products (syn gas) are brought to surface through another well con-nected hydro dynamically to the reac-tion chamber. The chemical reactions are same as in the surface gasifiers. Thus operationally, it involves drilling vertical, inclined and horizontal wells and establishing hydraulic connections between the wells in precise manner through permeable channels. Then the working requires compressing and injecting air (or oxygen enriched air) and steam into the seam and producing the hot product gas. The gases are then cooled and processed by removing pollutants. Some associated liquids are required to be separated as well as particulate matter and H2S gas. We note that drilling, injecting and produc-

ing gases as well as gas processing are the routine operations in the upstream hydrocarbon industry. The modern technological progress in the depart-ment of drilling long horizontal wells with very precise control on the well trajectory is expected to do miracles in UCG. Figure 3. “Logging while drilling” is another technology which will impact the UCG operations significantly. The EOR technique In-situ combustion has lot of similarity with UCG process. The modern techniques are developed for igniting the surface heavy oil for In situ combustion. The same can be adopted for UCG wells. ONGC, in India are world leaders in the field of in-situ combustion for recovering heavy oil.

UCG and Environment

It is clearly seen that the “ash” is left un-derground in the UCG method. The par-ticulate matter is the principle polluter causing the cardio-vascular deceases. This part is very safely separated and is never let in the atmosphere. Sulfur dioxide is another dangerous pollutant associated with normal burning of fossil coal or power and other industrial uses responsible for acid rains. Here the

reaction chamber has reducing en-vironment and sulfur is converted to H2S. In oil industry many technolo-gies are available for removing H2S from the gas stream. The operation is called sweetening the gas. Thus UCG takes very good care of solid, liquid and gaseous pollutants.

As stated above CO2 is one of the major Green House Gas responsible

Figure 2: UCG: Essential

Figure 3: Accuracy in inseam drilling

for the global warming. UCG offers a unique opportunity to separate CO2 before combustion from the syn gas. In Carbon separation and sequestration separation is a difficult and expensive first step. This step is facilitated in UCG. As far as sequestration is concerned a lot of research and experiments are required. However, the deeper coal seams which are not to be subjected to gasification or any other use in fu-ture offer attractive ultimate “Home” or CO2. The coal is an excellent adsorbent of CO2. The gas once adsorbed will remain so as long as it is not depres-surized. Only subsequent geological event of up-lifting o the strata can lead to such eventuality in geological time scale! There are successful case histories of injecting CO2 in subsurface aquifers. Figure 4. This is also pos-sible. It must be underlined that these are only possibilities at this time but extremely promising. The experience and technologies of upstream oil and gas industry can be of great help or sequestration also. Enhancing of oil recovery of nearby oil reservoirs by CO2 flooding opens another possibility for CO2 sequestration.

UCG & EROEI

There is price to be paid for everything one desires to do. UCG process in-volves extracting energy as well as the feed stock for petrochemicals from the coal by converting coal into gas in –situ. Over years the process has become efficient and the latest Rus-sian technology claims to recover 78% of the energy. Since the gas can be

Figure 4: CO2 Storage Projects - current & proposed

8 Ju ne 2009


converted into power efficiently, and all the energy required for mining, lifting, handling coal and ash is eliminated; the overall efficiency is expected to be more. Similarly, fertilizer, methanol and other chemical application require the gasification as a first stage. The same is achieved by UCG.

Figure 5: Schematic view of Underground coal Gasifier Plant

The real issue will be the energy re-quired for sequestration. It is neces-sary to do a very careful life cycle analysis. The process of separation of CO2, compression, transportation to the sequestration site and then injection into formation have various capital and recurring cost items. With

all these “Energy cost” is also associ-ated. Irrespective of the cost of energy and differential costs in various energy forms; it is absolutely necessary that the net energy gained from the total operation over the life cycle be positive. It is not unusual that tax breaks, sub-sidies, controlled administered pricing and host of other factors obscure the basic objective truth. Putting in say 100 Joules and getting back 80 Joules mat at times make business sense but it is not sourcing energy!

However, in case of UCG without se-questration it has huge positive energy balance. Figure 5.

Conclusion

Considering 1. The overall importance of energy in sustaining economic growth 2. The projected import dependency in conjunction with emerging global energy scene 3. The environmental aspects of pollution resulting from fossil fuels; UCG is a promising technology and India need to pursue the same vigorously with the sense of urgency.

Ju ne 2009 9


Dynamic optimization of Semi - regen-erative (SR) reformer over the entire cycle length (time between Start of Run & End Of Run) is vital for keeping product quality and yield (both liquid & gas) under refiners’ control. This will also lead to increase in cycle length considerably. To achieve this, a good control on operating variables with some continual changes over the time is necessary. With proper analysis of catalyst behavior & constituents, reac-tion equilibrium, and importantly - on time analysis of gas & liquid streams, it is indeed possible to attain optimum product quality, vis-à-vis, benzene re-duction in MS pool without sacrificing product yield. NRL has done it suc-cessfully in their Semi- Regenerative (SR) Reformer. A case study of this has been presented below.

NRL Motor Spirit Plant

The Purpose of the Motor Spirit Plant of Numaligarh Refinery Ltd. is to utilize the Straight Run Naphtha from Crude Distillation Unit to produce Motor Spirit of Euro-II & Euro-III grade with addition of the Isomerization Unit. It is designed to produce 185TMT of Motor Spirit per year conforming to both EURO-II & EURO-III specifications. The technol-ogy licensor is M/S AXENS, France. It consists of three units –Naphtha Hydrotreating, Catalytic Reforming & Isomerization.

The Refiner’s Objectives

Benzene Management

Benzene content being a critical target in Euro III grade MS, one prime objec-tive is to religiously maintain less than 1vol% benzene in the total MS Pool. This has been achieved by maintain-ing benzene in reformate at 1.5vol% & diluting the rest of the pool with

Dynamic Optimization of Motor Spirit PlantDipak ChakravartyDirector (Technical), NRL

Dhananjoy GhoshGeneral Manager (Operation), NRL

Rupam SarmahDeputy Manager (Operation), NRL

zerobenzene Isomerate available from the Isomerization Unit.

Increasing catalyst cycle length

From the economic point of view, main-taining the design cycle length & even trying to exceed it becomes a critical objective for the refiner. With carefully planned operation, NRL has been suc-cessful in achieving increased catalyst cycle length beyond the guarantee cycle provided by the licensor.

Dynamic control of benzene in reformate – a case study

Benzene control strategy

The following methodology has been followed to identify the root cause of benzene upset (increase of benzene in reformate) which actually happened in NRL.

Benzene precursor in feed ■ Identify & remove precursor in feed Con-

trol on upstream column operation (splitter) Benzene formation by reaction ■ Identify the adverse reactions Identify the factors contributing to adverse reactions Eliminate the factors.

Benzene precursors in feed

Methyl-Cyclo Pentane (MCP), Cyclo-Hexane (CH), Native Benzene (BZ), n-C6 Paraffins (n-C6P)

Conversion thumb rule (at 25 bars):30% of MCP to benzene. ■98% of CH to benzene. ■100% of BZ to benzene. ■20% n-C6P to benzene. ■

From the trend (Fig-1) it can be observed that benzene precursors in feed were steady or even lower than previous. So the benzene formation due to precur-sors can be partly eliminated. Upstream splitter column was further adjusted

10 Ju ne 2009


(increase in reboiling & reflux ratio) to minimize the benzene precursors.

Benzene formation through adverse catalytic reactions

Following are the known benzene form-ing reactions in the catalytic reformer-

Hydro- dealkylation (HDA) reaction ■Hydro-cracking reaction ■Paraffin dehydroyclization ■

To identify the reaction responsible, one has to observe effects of each reaction as illustrated below –

Effects of HDA reactionH2 purity will come down slightly. ■CH4 will be marginally high. ■No significant change of total paraf- ■fins & aromatics in product.No significant change in liquid ■yield.

Effects of Hydrocracking reactionH2 purity will come down substan- ■tially.Increase in C3+C4 yield & decrease ■in liquid yield.Decrease in C1 production related ■to C1-C4 cut.Total aromatics in product will in- ■crease.Decrease in delta T in last reactor ■

Some historical trends are presented to investigate into the situation –

Observations made from the graphical trends (Fig 2 – Fig 6)

Minor increase in LPG yield & minor ■fall in liquid (C5+) yield.Decrease in H2 purity of recycle ■gas.Decrease of C1 in comparison with ■C1-C4 in recycle gas.Increase of aromatics in product. ■Decrease in paraffins in product. ■

All the above observations are strongly indicating that benzene contribution in reformate was probably due to more cracking severity rather than Hydro-dealkylation reaction.

The next approach was to find out factors contributing cracking reactions. Cracking reactions occurs mainly due to –

High pressure operation of re- ■former.

Ju ne 2009 11


Feed with high end point (FBP). ■High severity (WAIT) operation. ■High acidity (chlorine content) in ■catalyst.Dry operation (low equilibrium mois- ■ture in recycle gas).

High pressure operation of reformerNRL CRU design operating pressure ■at 26 bars was in the higher side amongst all SR reformers.The high operating pressure was se- ■lected initially for LPG maximization & feeding H2 rich gas to PSA unit (Hydrogen plant) without boosting compressor.Scope for pressure reduction ■was investigated and found that there is some margin for pressure reduction without any hardware change.

Following observations were drawn from the trends (Fig 7 – Fig 10)

Feed boiling range was steady ■throughout the period with FBP at around 150 deg C.No significant change in reactor dif- ■ferential temperatures.WAIT remains in the range of 506 to ■508 deg C.Water dosing rate was almost steady ■at around 4 ppm of feed.Recycle gas moisture showing ■downwards trend. Chlorine dosing rate was high at ■around 0.8-1 ppm of feed

Summary of observations

High pressure operation of reformer along with higher chlorine dosing rate and low equilibrium moisture in recycle gas is suspected to be responsible for more acid activity of the catalyst.

12 Ju ne 2009


Following actions were taken subse-quently -

System pressure reduced by 2.5 ■bars to suppress hydrocracking & HDA reaction.C2Cl4 dosing rate adjusted to 0.4 ■ppm of feed rate to reduce catalyst acidity.Reactor temperature profile was ■adjusted by reducing last reactor WAIT by 4 deg C. This is to reduce cracking & HAD reaction severity which is more pronounced in last reactor due to large catalyst volume & higher bed average temp.

The subsequent trends show the im-pact of system pressure reduction on product yield .Liquid & H2 yield has increased after reduction of system pressure, whereas LPG yield has de-creased. This has helped in overall economics of the plant.

Dynamic control – increasing cycle length

NRL has been strictly maintaining following guidelines and approaches while operating the CRU:

Operating CRU on the merit of the ■feed.Severity as per product demand. ■

Reactor temperature adjustment as ■per differential temperature profile (deltaT).Control on catalyst chlorine. ■Maintain recycle gas H2 purity. ■

Ju ne 2009 13


Feed to NRL CRU & its propertiesReactor severity adjustment as per ■octane response.Higher IBP & FBP in feed requires ■less severity for same octane re-sponse, does saving catalyst life (reducing coke lay off).As feed FBP is limited with coking ■tendency, it is preferable to maintain higher IBP (>100 deg C).

Reactor severity as per product (blend) demand

Reactor severity adjusted so as not to have quality give way.

NRL CRU present WAIT during ■EURO-II MS mode is 511 deg C and octane response is 99+. This is to facilitate additional naphtha blending in MS pool to increase MS production (taking advantage of higher benzene & aromatic tolerance in product specification)NRL CRU present WAIT during ■EURO-III MS mode is 506 deg C and octane response is 98. This is to avoid quality give way in octane.

Adjustment of reactor temperature profile

It is not necessary to maintain flat ■temperature profile always.DeltaT of last reactor to be observed ■closely. If required inlet temperature of last reactor can be lowered to have sufficient deltaT

Control on catalyst chlorineCatalyst chlorine is to be closely ■monitored.

SR Catalytic reformer with higher ■operating pressure (like NRL) needs catalyst chlorine on lower side (around 0.7 to 0.8%)Check for Recycle gas HCl periodi- ■cally, recycle HCl can give indirect measurement of recycle moisture, if online analyzer is not perform-ing. Water dosing is to be adjusted accordingly. The effect is to be monitored through catalyst chlorine content analysis periodically

The trend in Fig-14 shows recycle gas HCl goes down with reduction in feed water dosing rate and the trend in Fig-15 shows coke buildup in CRU cata-lysts which is very slow and steady.

Maintaining recycle gas purity

Operation below design recycle H2 purity is to be avoided because this will lead to low H2:HC mole ratio & considerably low H2 partial pressure resulting in faster coking rate.

Conclusions

By closely adhering to these operating practices, the overall benzene manage-ment in the MS pool has become easier

for NRL. NRL has also succeeded in increasing cycle length by almost 50%(even more), able to optimize ( i nc rease ) l i q -uid & hydrogen yield, thus getting good economical benefits.

14 Ju ne 2009


Introduction

Bottom hole temperature in the range between 50 Deg C – 70 Deg C is en-countered quite frequently while drilling of oil and gas wells, by almost all op-erators across the globe. Temperature in this range is experienced mostly in shallow wells or in wells located in mature / depleted reservoirs. However even today, cement slurry designing for casing cementation of wells with low / moderately low (50 – 70 Deg C) bottom hole circulating temperature is a challenging issue. The situation becomes critical when the bottom hole temperature is lower than 50 Deg C.

Ideally designed cement slurries needs to be of desired density and should possess adequate thickening time under field temperature and pressure conditions to provide sufficient operational time to carry out cementation job. In addition the slurries used for production casing cementation should have minimum free water separation, should be stable under operational conditions, should possess minimum fluid loss and short transition time with right angle set characteristics. For operational requirement they should

Smart cementing solutions for wells with low bottom hole circulating temperaturesSatinath Banerjee, Chief Chemist and Debashish DasguptaDGM (D) Institute of Drilling Technology, ONGC,

also exhibit good rheological behaviour as it facilitates efficient placement and ef-fective mud removal during cementation. The designed cement slurries should also have early strength development char-acteristics and sufficient compressive strength development to meet manda-tory requirements within least waiting time (minimum WOC). Additionally the designed cement slurry should be gas tight for inhibiting gas migration / inter zonal communication and very low set cement permeability when used against gas zone and should be financially attrac-tive, eco-friendly and non-hazardous.

Scenario in ONGC (BHCT range of 40 – 70 Deg C)

On an average more than 50% of the wells in ONGC have BHCT in the range of 40 – 70 Deg C for the production casing cementation as being shown in the Figures 1 & 2.

Prevailing Practices in ONGC

The concept of designing cement slurry system for wells with low / moderately low BHCT with simultaneous total control of all crucial parameters is still

Figure 1: BHCT Ranges of well in ONGC (2000 – 2005)

STATUS OF ONSHORE WELLS IN DIFFERENTBOTTOM HOLE CIRCULATING TEMP. RANGES

(2000~2005)

20

100

58

39

87

57

23

14

97103

2217

86

73

2821

80

70

18

0

20

40

60

80

100

120

<50 50-70 70-90 >90

BHCT Ranges (Degree Centigrade)

NO

OF

WE

LL

S

2000-01

2001-02

2002-03

2003-04

2004-05

a grey area. Achieving all cement slurry parameters simultaneously to desired levels is extremely difficult and as a practical approach cement slurry is designed in-house, wherein at least one crucial parameter is compromised due to technical reasons. The other possible option to obtain somewhat better results is by availing the services of branded service providers. They with their exotic patented additives and processes may deliver better results but surely for an exorbitant price and without technology transfer commitment.

Present R&D Endeavor

Typically, wells having low / moderately low BHCT are abundant in Cauvery Asset / Assam Asset although wells with similar bottom hole conditions are also encoun-tered in several other fields of ONGC.

The present study was performed with reference to Cauvery Asset, consider-ing it to be an ideal representative for such wells (BHCT range of 55 – 67 Deg C). However, in other fields of ONGC, wells having BHCT lower than 50 Deg C and BHCT as low as 40 Deg C is not uncommon. Designing cement slurries for such low BHCT wells with all param-eter under total control is extremely dif-ficult. Under the present study cement slurries were formulated for the entire BHCT range of 40 - 70 Deg C.

The Cauvery Asset has plans to drill a number of wells in four of its fields (viz. Kovil Kalappal, Vijayapuram, Kuttalam and Kamalapuram) where the bottom hole temperature (BHCT) is in the range of 55 – 67 Deg C. With the existing fa-cilities and with available conventional cement additives, the Asset team is experiencing problem in designing suit-able cement slurries for application in these fields without compromising in one or more of crucial parameters (eg. fluid loss / rheology / thickening time / compressive strength).

Ju ne 2009 15


Based on information received from Cauvery Asset, the following conditions (Table -1) were used / observed for per-forming the experimental work.

The fol lowing slurry parameters (Table - 2) have been targeted to be achieved to perform cementation of these wells.

Conventional Approach

Cement slurry system designs for these low BHCT wells by using only conventional dispersant / fluid loss control additive / accelerator are not promising.

The results of these attempts are given in Table 3 as under:

Thickening time of cement slurry should be sufficient to enable an op-erator to safely place the slurry to the predetermined depth. Some margin of safety is required to be included so as to cover up any time loss due to mechanical break down while pumping slurry. But unnecessarily long thicken-ing time should be avoided as exces-sive thickening time causes:

Annular rings against permeable ■zones to cause gas migrationCauses water pockets and severely ■affect the quality of cementation

In shallow, low BHCT wells unnec-essarily long thickening time can be shortened by the use of set-accelerating additives. In the results presented above, it was observed that

at moderately low BHCT of 60 Deg C, conventional formulation with only fluid loss control additive does not set upto 350 minutes. Hence there is requirement of addition of a set ac-celerating additive. Common accel-erators are calcium chloride (CaCl2), sodium chloride, gypsum and sea water, among which calcium chloride is mostly used in the industry. Typi-cal concentration of CaCl2 generally used (in low temperature application) is about 4% BWOC. From the Table - 3 (Sl No 5, 8 & 10) it is observed that addition of CaCl2 for cement slurry formulation has profound undesirable effect (increase in fluid loss and poor rheology). Therefore, while designing

Sl. No

Name of Field / Location

Target Depth (m)

Desired Sp. Gr of

Cement Slurry

Bottom Hole Temperature Bottom Hole Pressure

(psi)BHCTDeg C

BHSTDeg C

1 Kuttalam 2500 1.9 63 101 45002 Kovil Kalappal 1900 1.9 55 90 35003 Kamalapuram 2400 1.9 60 94 45004 Vijayapuram 2600 1.9 67 107 4500

Table 1 : Cauvery Asset field parameters

Sl. No Parameter Desired value

1Thickening Time, Minutes(In temperature range (BHCT = 55 – 67 Deg C / RT = 30 mins / Break of 15 mins after 60 mins / Pressure = 3500 – 4500 psi)

200

2 Initial Consistency, Bc (Maximum) 103 Fluid Loss, ml / 30 mins (Maximum) 2004 Free Water Separation, % (Maximum) 1.45 Critical velocity, ft/ sec in 3“ equivalent diameter (Maximum) 6.0

6Compressive Strength, psi (Minimum)BHST in the range 90 – 107 Deg C / pressure = 3000 psi, time = 24 hrs

2000

Table 2: Targeted Cement Slurry Parameters for Cauvery Fields

cement slurries at low / moderately low BHCT by addition of accelerator, it is essential to add high dosage of fluid loss control additive to counter the effects of increase in fluid loss of the cement formulation. However addition of high dosage of fluid loss control ad-ditive also again resulted in increase of both the thickening time and rheology. Since the effect of set accelerator and fluid loss control additive on thickening time and fluid loss control is diagonally opposite, it is nearly impossible to de-sign slurry with adequate parameters for production casing cementation at low / moderately low BHCT using both the additives simultaneously.

The minimum dosage requirement of CaCl2 is 1.50 % BWOC in combination with additional fluid loss control agent & dispersants to achieve thickening time near the targeted thickening time of around 200 mins. At these dosage (Sl No. 8) the rheology of the cement slurry is very poor (Critical Velocity, Vc = 12.2ft / sec in 3“ equivalent diameter pipe) and it is very difficult to attain turbulent flow regime with such poor rheology. With higher dosage of CaCl2 (eg. 2.0 % BWOC) though the thickening time achieved near the desired value but both the rheology and the fluid loss increases beyond control / acceptable limits. Poor rheology results in poor cementation, as rheology of cement slurry governs mud displacement in the annulus.

< 50 Deg C8%

>90 Deg C10%

70~90 Deg C37%

50-70 Deg C45%

< 50 Deg C

50-70 Deg C

70~90 Deg C

>90 Deg C

DISTRIBUTION OF ONSHORE WELLSUNDER DIFFERENT BHCT RANGES

(AVERAGE PERCENTAGE OF 2000~2005)

Figure 2: Distribution of onshore wells for various BHCT ranges

16 Ju ne 2009


Sl. No BHCT Deg. C

CompositionThickening Time (mins)

Fluid Loss(ml/30 min)

RheologyVc (ft/sec) in 3“

equiv. Dia. C W DO60 % BWOC

DO65% BWOC

CaCl2% BWOC

1 60 100 44 0.7 0.4 - Not Set upto 350 min - -

2 60 100 44 0.8 0.4 0.5 Not Set upto 350 min 165 -

3 60 100 44 0.6 0.6 1.0 220 549 -4 60 100 44 1.0 0.2 1.0 285 190 10.505 60 100 44 1.0 0.4 1.0 295 175 9.836 60 100 44 1.0 0.6 1.0 - - 9.857 60 100 44 0.7 0.4 1.5 195 - -8 60 100 44 1.0 0.4 1.5 260 234 12.209 60 100 44 1.0 0.5 1.5 332 - -10 60 100 44 1.0 0.4 2.0 230 290 14.3

Table 3: Cement Slurry Parameters with conventional additives

Similarly if fluid loss is not controlled several serious consequences may occur which may lead to cement job failure or poor cementation job. If the filtrate from the slurry invades the for-mation, it can be harmful in number of ways.

It can causes premature dehydration ■of slurry which can lead to annulus plugging, incomplete displacement, annular leakage etcIt can change slurry rheology and ■consequently decrease mud re-moval efficiencyIt can damage production zones by ■cement filtrateIt can also change the other pa- ■rameters of the cement slurry, viz. slurry yield, thickening time, pump-ability etc

The best possible design (Sl No. 5 in Table - 3) with CaCl2 (1.0% BWOC) yielded a cement slurry with thickening time of 295 mins, fluid loss of 175 ml / 30 mins and Vc = 9.83 ft / sec in 3“ equivalent diameter pipe. Here the fluid loss is under control and the rheology is though still very poor but reduced from the slurry design at Sl. No 8 at the expense of increased thickening time due to reduction in set accelera-tor dosage. For practical purpose this design (Sl No. 5, Table - 3) is at best which can be achieved by conventional approach.

Alternate Approach

On the basis of experiments detailed above it is well realized that by fol-lowing conventional methodologies it may not be possible to design a ce-

ment slurry system where there will be total control over all the crucial slurry parameters such as low fluid loss, good rheology, good stability, nil free water separation, adequate thicken-ing time for placement and desired compressive strength development for minimum WOC period.

It is also realized that to obtain the above mentioned criteria, it is neces-sary to incorporate a suitable material which will have profound influence on the control of all these crucial pa-rameters. Furthermore the selected material should have high pozzolonic reactivity so as to able to participate in the chemical reactions towards reduc-tion of thickening time at low bottom hole temperature. The selected material also should be compatible with other conventional cement additives, easily available from indigenous sources, be low cost material, be non-hazardous and be eco-friendly. Moreover from our previous experience of designing slurries by adopting packing technol-ogy it is understood that if the material chosen is of sub micron size it can filled up the void space between the solid cement particles and thereby would exhibit easy mixability at reduced water and subsequently result in reduce fluid loss of the designed slurry.

Among the indigenously and com-mercially available materials which have pozzolonic activity and are of sub micron size, amorphous micro silica - densified (SM-1) can be regarded as a prime contender. It is silicon based material and is expected to perform the following functions:

1. Fill the voids between the cement particles resulting in a compact blend exhibiting easy mixability at reduced water and thereby reducing fluid loss and free water separation in formulated cement slurry.

2. Reduce thickening time due to high pozzolonic activity of amor-phous micro silica - densified

3. Enhance rheological character-istics by the lubrication effect resulting from the sphericity of the basic particles.

4. Accelerate early strength devel-opment process and increase compressive strength due to reduce mixing water requirement and high reactivity.

Fine particles of silicon based materi-als (crystalline form) are widely used in slurry design for oil well cementation. But its applicability is considered in situations where the BHCT is above 1100 C. In these cases the main pur-pose of addition of crystalline silicon based materials is to inhibit strength retrogression at high temperature and increase compressive strength. Amor-phous silicon based materials have not been effectively used for cement slurry designing for wells with low / moder-ately low BHCT.

Based on these theoretical concepts, evaluation of the performance of amor-phous micro silica in cement slurry de-signing for low / moderately high BHCT wells is considered as an alternate approach for the total control of crucial parameter of the cement slurry required for obtaining good zonal isolation.

Ju ne 2009 17


Results and Discussions

In meeting the objectives of this study, cement slurries were successfully designed for low BHCT wells. It is ob-served (Table – 4) that incorporation of SM-1 in the formulations have resulted in simultaneous control of all crucial pa-rameters which was earlier not possible through conventional approach. SM-1 in the formulation have also reduced the thickening time and fluid loss of cement slurry, improved slurry rheol-ogy and contributed to early strength development.

From the above results (Table – 4) it is clearly evident that with IDT developed formulations all the crucial cement slurry parameters have been brought under total control. For the BHCT range of 55 – 67 Deg C in the four different fields of Cauvery Asset, thickening time of the for-mulated cement slurries are between 237 – 191 minutes, which is very close to the targeted thickening time of 200 minutes. All the slurries have nil free water separa-tion, low fluid loss (under 225 ml/30 min), good stability, excellent rheology at BHCT (Vc in the range of 4.14 – 5.48 ft/sec) and early strength development character-istics with good compressive strength within 24 hrs (more than 3600 psi), which are very close to all the targeted slurry parameters. Obtaining all of the above mentioned parameter in this manner was not possible earlier through conventional

Sl. No. Particulars Kovil Kalappal

Field Kamalapuram

Field Kuttalam

Field Vijayapuram

Field

1 BHCT, Deg. C 55 60 63 672 BHST, Deg. C 90 94 101 107

COMPOSITION3 Cement 100 100 100 1004 Water % BWOC 46 46 46 465 SM-1 % BWOC 10 10 10 86 DO60 % BWOC 0.4 0.4 0.4 0.57 DO65 % BWOC 0.6 0.6 0.6 0.68 D47 % BWOC 0.1 0.1 0.1 0.1

SLURRY PARAMETERS

9

Thickening Time (mins)RT = 30mins, with 15 mins break after 60 mins Pr = 4500 psi

237 215 207 191

10 Fluid Loss (ml/30 mins) at BHCT 221 223 225 123

11 Free Water (ml) at BHCT Nil Nil Nil Nil12 Rheology at BHCT PV 56 54 60 73

Rheology at BHCT Yp 10 10 10 7

Rheology at BHCT Vc Ft/sec * 4.98 4.14 4.84 5.48

13 Stability Stable Stable Stable Stable

14Compressive Strength (Psi)At BHST / 3000 psi

8 Hrs 1250 - - -24 hrs 3640 3710 4300 385096 hrs 5300 - 4900 4000

Table – 4 : Cement Slurry Parameters when designed by Alternate Approach API Class G

cement has been used and Slurry Sp.Gr = 1.90, * Herschel Bulkley Model

cement slurry designs and IDT developed cement slurries are superior in all counts. A typical consistency plot using SM-1 is given in Graph – 1.

Due to the early strength development characteristics, WOC period can be substantially reduced. As per oil industry norms compressive strength of 500 psi is required for resuming further operations and compressive strength of 2000 psi is required prior to perforation. The IDT developed cement slurries attain com-pressive strength of 1250 psi within 8 hrs only which is far less than the commonly adopted WOC period. Thus implemen-tation of IDT developed cement slurries would thereby also result in cost savings due to less rig time requirement (savings on OPEX).

In recent times ONGC has in principle decided to drill hi-tech wells in onshore fields where the conventional vertical wells were the majority. For hi-tech wells the stability of cement slurry under bottom hole conditions is very critical for obtaining success of a ce-mentation job. IDT developed cement slurries are very stable under bottom hole condition and are ideal for appli-cation under such conditions. Attaining

Graph 1: Consistency Plot

Composition : C100 + Water - 46 + DO60 – 0.4% + DO65 – 0.6% + SM-1 – 10% + TBP – 0.1% (BHCT = 600 C, RT = 30 mins, Break of 15 mins after 60 minutes, Pressure = 4500 psi)

18 Ju ne 2009


Sl.No

Composition Thickening Time (mins)

RT = 30mins, with 15 mins break after

60 minsPr = 4500 psi

Fluid Loss(ml/30 mins)

at BHCT

Rheology At BHCT

C W SM-1 DO60 DO65 D47 CaCl2 Vc Ft/sec

1 100 46% 10% 0.4% 0.6% 0.1% — 198 223 4.14 *

2 100 44% — 1.0% 0.45 0.1% 1.5% 260 234 12.20

Table – 5 : Comparison of IDT Formulated Slurry with Conventional Slurry

* Harschel Bulkley Model

Sl. No. Particulars

SLURRY DESIGN SLURRY DESIGN SLURRY DESIGN SLURRY DESIGN

CAUVERY IDT CAUVERY IDT CAUVERY IDT CAUVERY IDT

1 WELL KKDB - KADH - KPDI - VJDB -2 FIELD Kovil Kalppal - Kuthalam - Kamalapuram - Vijayapuram -3 SLURRY DENSITY 1.90 1.90 1.90 1.90 1.90 1.90 1.90 1.904 BHCT, Deg. C 55 55 63 63 60 60 67 675 BHP, PSI 3500 4500 4500 4500 3400 4500 4500 4500

COMPOSITION

6 SM-1 % BWOC - 10 - 10 - 10 - 8

7 DO60 % BWOC 0.2 0.4 0.3(FL-011) 0.4 0.3 0.4 0.4 0.5

8 DO65 % BWOC 0.1 0.6 0.3(FR-022) 0.6 0.2 0.6 0.3 0.6

SLURRY PARAMETERS

10 Thickening Time (mins) ) at BHCT 205 237 215 207 215 215 250 191

11 Fluid Loss (ml/30 mins) at BHCT 1379 221 1583 223 1050 223 1279 123

12 Rheology at BHCTVc (Ft/sec) 10.55 4.98 9.48 4.84 8.78 4.14 8.33 6.26

Table – 6 : A Comparison of slurry designs presently being followed for the Production Casing

Cementation at BHCT below 700C in Assam Asset Vs IDT’s formulation

Sl. No. ParticularsSLURRY DESIGN SLURRY DESIGN SLURRY DESIGN

ASSAM IDT ASSAM IDT ASSAM IDT

1 WELL GKFT R#135A - LKES - PDAEI -2 FIELD Geleky Rudrasagar - Lakwa - Panidihing -3 SLURRY DENSITY 1.90 1.90 1.90 1.90 1.90 1.90 1.904 BHCT, Deg. C 55 55 55 65 63 60 605 BHP, PSI 5500 5500 4500 5500 4500 7000 4500

COMPOSITION

6 SM-1 % BWOC - - 10 - 10 - 107 DO60 % BWOC 0.6 0.5 0.4 0.6 0.4 0.6 0.48 DO65 % BWOC 0.3 0.2 0.6 0.3 0.6 0.3 0.6

SLURRY PARAMETERS

10 Thickening Time (mins)) at BHCT 312 350+ 237 462 207 350 215

11 Fluid Loss (ml/30 mins) at BHCT 380 343 221 215 223 260 223

12 Rheology at BHCTVc (Ft/sec) 9.88 7.15 4.98 8.19 4.84 8.13 4.14

Table -7 : A comparison of slurry designs presently being followed for the Production Casing

Cementation at BHCT below 700 C in Assam Asset Vs IDT’s formulation

such stability is very dif-ficult with conventional cement slurries.

In comparison to con-ventional cement slurries (Table – 5), with the use of SM-1, the quantity requirements of costliest imported cement addi-tive i.e. fluid loss control additive is reduced and would results in cost sav-ings over and above the technical advantages.

Comparison of IDT formulated cement slurry with field implemented slurries

Direct comparison of field implemented ce-ment slurry designs of Cauvery Asset and As-

sam Assets vis-a vis IDT de-veloped cement slurries are given in Tables – 6 & 7. Ce-ment slurries that have been used for production casing cementation in the field but in these slurries it was not pos-sible to simultaneously bring all crucial slurry parameters under control. To some extent it was always necessary to compromise at least on one of the crucial parameters com-pelled by technical reasons. The use of IDT formulated ce-ment slurry would overcome such technical shortcomings and enhance performance resulting in good production casing cementation.

To meet the requirement for other fields of ONGC where

Ju ne 2009 19


BHCT is below 50 Deg C additional studies were performed and cement slurry were formulated for wells with BHCT of 40 Deg and 48 Deg C, the details of which are given in Table – 8. For such low temperatures also, the developed cement slurries attained all desired properties and are best suited for such applications.

Conclusions and Recommendations

The major conclusions drawn from this study are:

1. Conventional cement slurry de-sign is not ideal for production casing cementation of wells with low / moderately low BHCT (40 – 70 Deg C). In these cement formulations, set accelerator is required for which purpose

Sl.No

CompositionBHCT Deg.

C

Thickening Time (min)

RT = 30 min, with 15 min break after

60 minsPr = 4500

psi

Fluid Loss(ml/30 mins)

at BHCT

Free Water (ml) at

BHCT

RheologyAt BHCT Stability

Compressive Strength

(Psi)at BHST / 3000

psi/ RT = 240 mins

C W SM-1 DO60 DO65 D47 PV Yp Vc 24 hr

1 100 46% 12% 0.4% 0.6% 0.1% 40 265 224 Nil 89 15 7.38 * Stable2470

(BHST 600 C)

2 100 46% 12% 0.5% 0.6% 0.1% 48 289 204 Nil 72 12 - Stable -

Table – 8 : Properties of IDT formulated cement slurries for BHCT of 40 Deg C and 48 Deg C

Water and Additive concentrations as percentage BWOC, Sp. Gr. of cement slurry = 1.90

SM-1 = Amorphous Micro Silica – densified * Herschel Bulkley Model

calcium chloride is mostly used in the industry. Addition of cal-cium chloride adversely affects cement slurry properties and all crucial parameter can not be simultaneously brought under control in the formulation

2. In cement slurry designs for such well the present practice is to compromise on any one param-eter due to technical reasons.

3. Cement slurry design for low / moderately low BHCT (40 – 70 Deg C) wells may be done with an alternate approach by incor-porating a suitable material in the slurry design which should have high pozzolonic reactivity and small particle size to fill up the void space between the solid ce-ment particles for exhibiting easy mixability at reduced water.

4. Amorphous micro silica – densi-fied form (SM-1) has been suc-cessfully used for cement slurry design for low / moderately low BHCT (40 – 70 Deg C) wells. It has shown excellent results with simultaneous total control of all crucial parameters such that ce-ment slurry can now be designed for any specific requirement within this BHCT range which was earlier nor possible.

5. Use of Amorphous micro silica – densified form (SM-1) in ce-ment slurry design helps in early compressive strength development and results in re-duction of WOC period leading to cost savings.

6. In ONGC about more than 50% of the wells cemented for produc-tion casing have BHCT under 70 Deg C and thus cement slurry designs incorporating amor-phous micro silica – densified form have tremendous potential for applicability in several of its fields.

7. Comparison of properties of presently used cement slurry designs with IDT formulated ce-ment slurries clearly show that IDT formulated cement slurries are superior than presently used cement slurry on all crucial pa-rameters.

ReferencesNelson, Erik B,: “Well Cementing”, ■Edited by., Elsevier Science Pub-lisher B.V., The Netherlands.Ghosh, S.N.: Cement and Concrete ■Science & Technology”, Volume I, Part I, ABI Books Private Limited, New Delhi - 110019 (1991) 361.

20 Ju ne 2009


202020 Ju ne 2009

Indian offshore operations started in Mumbai offshore in early 70’s. From

Mumbai offshore to Reliance’s start of production from India’s first deepwater green field facility is historic achievement since this is the largest and most com-plex deepwater development of its kind that too developed at a rapid pace.

India is going to be benefited immensely from the KG Basin D-6 gas production. India’s import dependence is likely to fall from current level and most impor-tant of all, India will be able to move from an oil economy to a cleaner fuel economy. Apart from reducing import bill India will be benefited with reduced subsidy bills and will be generating ad-ditional 8,000 MW of power every year. Also ONGC will be having substantial increase in their gas production after KG basin field coming on streamline from Apr 2010 which will complement further the energy supply for India.

Indian Deepwater comprises of total 42 % of total sedimentary basins area and most of the area is largely unexplored. Given the magnitude of Reliance & ONGC’s gas find in KG basin, prospec-tively is now under no doubt.

Total of 71 deepwater blocks are under various phases of exploration till NELP VII. Further government has offered 24 deepwater blocks in 8th round of NELP.

Out of these deepwater blocks Reli-ance and ONGC have made significant

Towards a Deeper SolutionNaresh KumarManaging Director Jindal Drilling & Industries Ltd

and President Petrotech Society

discoveries in deepwater. But these discoveries are yet to be developed and require huge investments Reli-ance D-6 development alone will at-tract around US $ 8 Bn. ONGC has planned to invest over US $ 5 billion for development of their discover-ies. Development of these fields will provide plethora of opportunities for the whole value chain - upstream and downstream both.

Deepwater discoveries in India

Both companies are operating 11 float-ers in Indian offshore water and have secured few more floaters which are yet to be deployed for their work program. And the hunt is still on to secure more deepwater rigs since the exploration activities tend to increase in deepwater due to new discoveries and addition of new blocks in Operator’s kitty.

Global annual energy consumption has more than tripled over the past 50 years, driven mainly by demand growth in the developing economies. And easy oil is depleting at a very fast pace to cater this demand. Currently world offshore energy production accounts around 35 % of total production. And deepwater production is just 6 % of the total production and expected to be around 12 % in year 2012. Post 2012 deepwater sector would be the seg-ment which will grow exponentially and land & shallow water production will see comparatively lower growth rate.

Deepwater is de-veloping into a long-term growth sector. Deepwa-ter oi l and gas world production is increasing rap-idly and output is expected to in-crease by almost 8 0 % o v e r t h e period to 2011.

Mr. Naresh Kumar (Managing Director Jindal Drilling & Industries Ltd & President Petrotech Society) has

received another feather in his cap by being nominated as Member, Executive Committee of prestigious International Association of Drilling Contractors (IADC), headquartered in Houston Texas, USA.

IADC is the global apex body since 1940 for Drilling Contractors worldwide and is dedicated for enhancing the interests of the oil-and-gas drilling and completion industry.

I am proud to announce that Mr. Kumar is not only the first Indian but the 1st Asian nominated on this prestigious 14 Member Executive Committee. The Committee comprises of Industry leaders of the Drilling Industry. The Committee is the body to enhance the industry standards, coordinate Research & Development of cutting edge technology, enhance HSE norms and coordinate global regulatory issues for Oil & Gas Industry.

Mr. Naresh Kumar has been the founder member & has served as First Vice Chairman of IADC south Central Asia Chapter.

He is also the founder member and President of Petrotech Society.

He is also the Chairman Oil and Gas Services Division - Confederation of Indian Industries (CII).

NELP RoundDeepwater blocks under NELP

Offered Awarded Relinquished OperationalNELP –I 12 7 7NELP -II 8 8 1 7NELP -III 9 9 9NELP -IV 12 10 10NELP -V 6 6 6NELP -VI 24 21 21NELP -VII 19 11 11Total 90 72 1 71

Source: ONGC & DGH

Ju ne 2009 21


From 4.5 million barrels per day (bpd) in 2007, deepwater oil production will grow to nearly 8 million bpd in 2011, whilst deepwater gas production will increase from 1.6 to over 3 million bpd equivalent over the same period.

Focus area in the deepwater explora-tion is in Latin America, West Africa and Gulf of Mexico, North Sea along with some south East Asian Countries including India.

Africa is expected to be the leading deepwater development area over the 2008–2012 period. Most of the IOC’s are working in the region and Shell’s Bonga on OPL 212 off Nigeria and Total’s Girassol on Block 17 off Angola are two most prolific finds in the World, considered Giant fields. Other than these two Elephant fields there are a variety of deepwater development going on –

Shell’s Bonga South West ■

ExxonMobil’s Bosi projects, ■Chevron’s Agbami and Total’s Akpo ■and Usan/Ukot – off NigeriaBP’s Greater Plutonio development ■in Block 18 and Block 31ExxonMobil’s Mondo, Saxi and ■Batuque discoveries FPSO devel-opmentNorsk Hydro and Sonangol’s Gim-■boa field via FPSOChevron the Negage f ield via ■FPSO

The Latin America region is dominated by Brazil’s Petrobras who has pio-neered in deepwater exploration. Main deepwater fields includes -

Tupi, Compos, Roncador, Marlim Leste, Marim Sul, Jubarte and Albacora Leste fields, Golfinho

Area will account for approximately 20 % of the total expenditure in the next 4-5 years.

The North America region is expected to account for over 20% of deepwater development capex over the 2008–2012 period. US Gulf of Mexico’s main deepwater fields in the DeSoto Canyon and Lloyd Ridge are –

Spiderman, Merganser, Vortex and San Jacinto Atlas NW

Petrobras is also operating in Cascade and Chinook fields via FPSO

“The ‘Golden Triangle’ of Africa, Gulf of Mexico and Brazil will account for three-quarters of global deepwater expenditure over the next few years. However, the emergence of Asia as a significant deepwater region should not be overlooked. Indonesia, Malay-sia and India all have development prospects on screen for the 2009-2013 period and the region should account for nearly 10% of deepwater Capex. Indian offshore will emerge as a domi-nant region for deepwater activities in South East Asia

Path ahead

Gas hydrates and Shale gas still being a far fetched reality, World can look for deepwater areas for their Energy needs. Big finds in Brazil & Africa are promis-

Year Name of discoveries Operator State/Area/Block Type2002-03 Dhirubhai-1 RIL KG-DWN-98/3 Gas

Dhirubhai-2 RIL KG-DWN-98/3 GasDhirubhai-3 RIL KG-DWN-98/3 GasDhirubhai-4 RIL KG-DWN-98/3 Gas

2003-04 G-4 ONGC KG Deep water GasDhirubhai-5 RIL KG-DWN-98/3 GasDhirubhai-6 RIL KG-DWN-98/3 Gas

Vasisha ONGC KG Deep water GasDhirubhai-7 RIL KG-DWN-98/3 GasDhirubhai-8 RIL KG-DWN-98/3 Gas

Dhirubhai-16 RIL KG-DWN-98/3 Gas2004-05 GS-15-East ONGC KG Deep water Gas

KG-DWN-98/2-D ONGC KG Deep water GasKG-DWN-98/2-A ONGC KG Deep water GasKG-DWN-98/2-U ONGC KG Deep water GasKG-DWN-98/2-W ONGC KG Deep water GasKG-DWN-98/2-E ONGC KG Deep water Gas

2205-06 Dhirubhai-18 RIL KG-DWN-98/3 GasDhirubhai-19 RIL KG-DWN-98/3 GasDhirubhai-22 RIL KG-DWN-98/3 GasDhirubhai-23 RIL KG-DWN-98/3 Gas

2006-07# KG-DWN-98/2-UD1 ONGC KG-DWN-98/2 GasMN-OSN-2000/2-2A ONGC MN-OSN-2000/2 Gas

2007-08# MN-DWN-98/3-A1 ONGC MN-DWN-98/3 GasMDW-4A

KG-DWN-98/2 ONGC GasKG-DWN-98/2-KT-1** KG-DWN-98/2

MN-DWN-98/3-B ONGC GasMDW-5 MN-DWN-98/3

Source: ONGC & DGH

Source: Douglas Westwood report on Deepwater

22 Ju ne 2009


Source: Douglas Westwood report on Deepwater

ing enough for the world to expedite the deepwater exploration. But bring-ing energy beneath the sea beds from these fields will require most complex developments ever, and technology will be the only key concern for E&P companies.

Transfer of technology & knowledge through collaboration, joint develop-ment initiatives will help companies to resolve complexity involved in the deepwater projects.

As far as India is concerned, it gives immense possibilities in terms of growth and challenges. Though deep-water area is around 38% of the total area awarded for exploration, it still is one of the least explored areas. For instance India’s well density is very less in offshore region, which is around ~ 1 well/000sq km and number goes far below then this when it comes to deepwater well density in India which is only 0.16 /000 Sq km.

Technology is the biggest constrain in development of deepwater project since Indian Companies are relatively inexperienced and are looking for collaboration in securing expertise in development of fields and services like - Deepwater & Ultra Deepwater Drill-ing Rigs, FPSO, Subsea Installations, Platforms, ROV’s, Subsea Pipelines installation and Vessels, experienced players get an opportunity to make their foot mark in Indian Deepwater scenario. Reliance is already de-veloping one of the most complex deepwater projects and ONGC has also taken a major step towards secur-ing sophisticated technology for the development by signing pacts with Petrobras, ENI and StatoilHydro to

pursue joint development of some of their discoveries.

These developments will not only fil-lip India’s endeavor towards securing energy for sustainable growth but will also provide immense opportunities for service sector.

Indian Government is also stepping up their efforts in creating more investor friendly environment, but issues like tax holiday ambiguity over gas production can not only hold back experienced

player to participate but can also ham-per development of current discoveries. Since Indian deepwater industry is in its initial phase, government should promote Indian service providers to develop technology & skills to cater upcoming huge demand for services. Petrobras the biggest deepwater explorer company is promoting local service providers by giving them the ex-clusive rights of building rigs & services in Brazil which will be observed in their operations. Further it should promote a policy frame work for the retention of technology in India. Apart from up-stream services, extensive network of pipelines will be required to distribute the gas to the end consumer which itself will be multibillion task.

India’s ever growing energy demand will soon increase the import dependency but optimal use of energy mix and ex-tensive exploration of deepwater can defer it. And we never know that D-6 might just be tip of the ice burg and eastern coast might be another GOM in making.

Ju ne 2009 23


Abstract

Opportune crude oils and their blends play an important role in increasing refinery profitability, whereas the risks are high because these usually come laden with contaminants such as de-stabilized asphaltenes, waxes and high metal content etc .The destabilized/precipitated asphaltenes and other contaminants can cause problems like stable oil-water emulsions, fouling of heat exchangers, catastrophic coking in furnace tubes, and leading to high maintenance costs and equipment losses. In such consequence, incom-

patible crude blends causes problems viz. flocculation and deposition of as-phaltenes etc. Therefore, determination of insolubility number (IN) and solubility number (SBN) are the key parameters in the prediction of flocculation when dealing with the incompatible crude oil blends.

Methods are presented and discussed for determination of insolubility number (I

N), and solubility number (SBN) of crude oil, and prediction of compatible scale for various crude oil blends. The results are also compared with the colloidal instability index (CII) for various crude oil blends, and a good correlation ob-served. This work also demonstrates the criterion to mitigate problems during the processing of incompatible crude oil blends within the refinery.

Background

Opportune crude oils have drawn a serious attention for oil companies to increase the gross refinery margin (GRM). Although crude oil blends are often being processed in the refineries but this practice has several constraints

Prediction of Crude Blend Compatibility- way to enlarge the Crude Processing SlateVivek Rathore, Tushar S Thorat, P V C Rao and N V ChoudaryCorporate R&D Center, Bharat Petroleum Corporation Limited

Vivek Rathore (Sr. Research Engineer) joined BPCL R&D in 2006. He completed Master Degree in Chemical

Engineering from IISc Bangalore and Bachelor of Engineering from RIT Raipur. His areas of expertise are processing of crude oil and crude oil blends, LPG Sweetening catalyst, Resid Up-gradation technology, alternative fuels and reaction modeling.

Dr. Tushar S Thorat holds Ph.D. in Chemistry from ICT (formerly UDCT) in Heterogeneous Catalysis. He has

over 15 years of experience in research and development. Since 2005, Dr. Thorat is Deputy Manager of the Corporate Research & Development Centre of Bharat Petroleum Corporation Limited. He is working in the areas of crude evaluations, crude compatibility and blending, high acid crude processing, bitumen, bottom of barrel and new product developments.

Dr. P V C Rao, Senior Manager, BPCL (R&D) has got 22 years of research experience in the area of Petrochemicals

and Refining. He has Ph.D. from IIT, Bombay and MBA from IGNOU. His areas of expertise are processing of opportune crude oils/blends, Biofuels, Sweetening catalyst, Bitumen, Resid Up-gradation, and Product development and Analytical sciences.

Dr. N V Choudary is presently working as Chief Manager at Corporate R&D Centre, Bharat Petroleum

Corporation Ltd., India. He has over 25 years of research experience in petroleum refining and petrochemicals. He holds MSc., and Ph.D., degrees in Chemistry. His areas of expertise include catalysis, adsorption, crude oils & processing of opportune crude oils/blends, bitumen, product development and biofuels. Dr. Choudary filed about 40 patents including 6 US patents granted, published about 60 research papers in referred journals and presented over 60 papers in national and international conferences.

of logistics such as non-availability of storage tanks/vessels, unwanted consequence of fouling in the pre-heat trains, heat-exchangers, and coking in the pipe still furnace tubes, etc. It may be caused by asphaltenes precipita-tion, oxidative polymerization and coke formation components in the oil. The related problems associated with floc-culation and deposition of asphaltenes can further increase the cost of oil recovery processes. Therefore, a bet-ter understanding of detail knowledge of factors that affect composition and physico-chemical structure of the crude oils is required.

Introduction

The crude oil components are broadly classified into four chemical classes based on differences in solubility and polarity. These components are called saturates (S), aromatics (A), resins (R) and asphaltenes (A). Above all,

24 Ju ne 2009


asphaltene is one of the major causes for fouling in the crude oil and their blends during refining processes. As-phaltenes represent a wide variety of hydrocarbon molecules. These are typi-cally polyaromatic in nature with some degree of alkyl substitution present and usually contain heteroatoms such as oxygen, nitrogen, sulfur and metal atoms in their structures. Asphaltenes is dispersed in the oil with the resins and this asphaltene-resin dispersion is dissolved into petroleum oils with aromatics (solvent) but opposed by saturates (non-solvents). Thus, the variation of the original composition takes place during blending of differ-ent crude oils. Hence, asphaltenes is held in petroleum oils in the delicate balance, and this balance can easily be disturbed by adding saturates or by removing resins or aromatics. Blending of oils can greatly change the overall concentrations at the molecular level to disturb this balance and precipitate asphaltenes.

Considering the hypothesis that resins and asphaltenes are always associated with each other. The oil behavior is also guided by solubility and aromatics-saturates balance. This postulation is reported and contributes to predict the blend precisely. Therefore, asphaltenes is one of the major contributors in the fouling problems associated with the refining processes. Hence, the fouling problems can be counteracted by the prevention of asphaltenes precipitation or even being close to the onset of precipitation. The prediction of fouling requires two dimensionless solubil-ity parameters. These parameters are called the insolubility number (I

N) and the solubility blending number (SBN). These parameters are determined by mixing individual crude oils with non-polar solvent (toluene) and with polar solvent (n-heptane). The point of incipient locates the asphaltene precipitation. The crude oils/blends are compatible when the volumetric SBN is greater than IN for any oil in the blends/streams. The region where SBN of any of the feed stream is equal or less than IN of any of the stream then it predicts the incompatibility behavior.

This work measure the compatibility parameters such as IN and SBN for as-

phaltenic crude oils such as Crude A, Crude B ,Crude C and Crude D. Results were compared with the theoretical models reported in the literature. The obtained compatible blends were also compared with colloidal instability index (CII) to predict the stable blend region.

Experimental Section

Material and Apparatus

Asphaltenic crude oil samples like Crude A, Crude B, Crude C and Crude D were selected for the experiments. Solvents such as n-heptane and toluene were used without any further purification.

The crude oils and their blends were examined by spot-test method and optical microscopy technique. In the spot test method, a drop of the blend of test solvent mixture and oil was put on a piece of filter paper and dried completely. If the asphaltenes are in-soluble, a dark ring or circle was seen about the center of the yellow-brown spot made by the oil. If the asphaltenes are soluble, the color of the spot made by the oil was relatively uniform in color. Alternatively, samples were also analyzed over an optical microscope with a magnification of 10x100 for the evidence of asphaltene precipitation. The physical properties of crude oil used in the study are summarized in Table 1.

Method

The determination of IN and SBN for a petroleum oil containing asphaltenes were done with the help of solubility of the oil in test solvent mixture at the minimum of two volume ratios of oil to test solvent mixture. The test solvent mixtures were prepared by mixing two solvents in various proportions.

One polar solvent (toluene) for the asphaltenes and one non-polar non-solvent (n-heptane) for the asphaltenes were used.These tests are generally classified on the basis of the selected solvents such as ‘toluene equivalence test’ and ‘heptane dilution test.

For the toluene equivalence, conve-nient volume ratios of oil to test solvent mixture were selected, for instance 0.1 and 0.2. Then various mixtures of the test solvent mixtures were prepared by blending toluene and n-heptane in vari-ous known proportions. Then volume of oil 1ml or 2ml was used and10 ml of test solvent mixture composed of varying ratios of toluene and n-heptane were added in oil and mixed well. After wait-ing 5 min at room temperature, solubil-ity or insolubility were determined for each of these samples by spot test &/or by optical microscope technique. When the asphaltenes were insoluble, a dark ring/circle was seen about the center of the yellow-brown spot made by the oil. If the asphaltenes were soluble, the color of the spot made by the oil was relatively uniform in color.

In optical microscope, in case of in-soluble asphaltenes, dark particles, usually in the range of 0.5 to 10 mi-crons were observed. The results of blending oil with all of the test solvent mixtures were ordered according to increasing percent toluene in the test solvent mixture. The desired value was between the minimum percent toluene that dissolves asphaltenes and the maximum percent toluene that precipitates asphaltenes. Additional test solvent mixtures were prepared with percent toluene in between these limits and determined if the asphaltenes were soluble or insoluble. This process was continued until the desired value was determined within the desired ac-curacy. This was considered as the first datum point for determining the insolu-

Table 1. Properties of crude oils used in this study

Properties Crude A Crude B Crude C Crude DDensity (g/cm3) @ 150 C 0.89 0.87 0.87 0.91Sp. Gravity at 60/600 F 0.88 0.86 0.87 0.900API Gravity 27.46 30.49 31.05 24.50Total Sulfur (%wt) 0.32 2.78 2.67 —Viscosity (cSt) @ 400 C 6.72 8.75 7.45 —TAN (mg KOH/gm) 0.90 0.09 0.19 0.17Pour Point (0 C) 27 –54 –27 –42

Ju ne 2009 25


bility number and solubility number. The second datum point was determined by the same process as the first datum point, only by selecting a different oil to test solvent mixture volume ratio.

For heptane dilution test, the preferred test liquid mixture was is n-heptane, with a continuous addition of n-heptane into the oil until asphaltenes just began to precipitate for determin-ing the third datum point. The above described method was same for the crude blends.

Results and Discussion

Determination of Insolubility Number (IN) and Solubility Blending Number (SBN)

The determination of the compatibil-ity or incompatibility of oil and their blends is the most significant part of this study. Asphaltenic crude oils like Crude A, Crude B, Crude C and Crude D crude were investigated. Figure (1) Shows that the compatibility of the individual oils with different proportions of a solvent (toluene) and non-solvent (n-heptane). Different convenient vol-ume ratio of oil to test solvent mixture (toluene and n-heptane) were selected and corresponding percentage of tolu-ene plotted on abscissa and ordinate, respectively. The ordinate intercept is considered as the IN of the crude oil, is shown in Fig 1.

The line intersecting the absissa for any finite value of the volume ratio of oil to test liquid then the absissa rep-resents test solvent mixture contains only n-heptane and zero toluene, and then;

The solubility blending number (SBN) is given by:

SBN = IN [1+100/HD] ----------------- (1)

Where HD is the abscissa intercept or was taken from the heptane dilu-tion test. For self compatible oils, the line slope would be negative and self incompatible oils the x-axis intercept is infinite, the SBN equal to the IN and equal to the percent toluene in the test liquid for any volume ratio of oil to test solvent mixture.

As described above method in the present study, IN is taken from Fig.1 and SBN is calculated from math-ematical relation between the param-eter (equation (1)). These parameters are shown for various crude oils at Table 2.

Prediction of Suitable Crude Blend Composition

In order to prepare the blends of oil to be compatible, the SBN of the mixture should be higher than the maximum IN of any of the individual oils in the mixture. The SBN of a mix-ture of oils from the mixing rule for solubility parameters is the volumetric average. It is known that the Crude oil is considered as colloidal solution made up of the pseudo components like aromatics, saturates, resins and asphaltenes. The Colloidal instability Index (CII) is expressed as the mass ratio of the sum of asphaltenes and its flocculants (saturates) to the sum of peptizers (Resins and aromatics) in a crude oil [14-16]. The CII is considered as a measure of relative stability, the higher the value, more unstable the blend and the CII is defined by the following equation:

CII = (Asphaltene + Saturates) / (Resins + Aromatics) --------------- (2)

The colloidal instability index is calcu-lated from the weight percentages ob-tained form SARA (Saturates, Aromatics, Resins and Asphaltenes) analysis.

CII Criteria Scale for Crude Blend

The literature revealed that crude blend compatible when the CII values below 0.7 and found incompatible where CII valve is greater than 0.9, but the CII value falls in the range of 0.7 - 0.9 that indicate uncertain region for compat-ibility. It has been observed that for several crude blends the CII values falls in the range of 0.7 – 0.9, the re-gion of uncertainty, thus for the crude blends having CII values in this range, the predictions on blend compatibility becomes complicated.

The present work demonstrates experi-ments to blend Crude A with Crude B, Crude C and Crude D to predict the compatibility.

Figure 1: Graphical presentation of IN for various crude oils

Table 2. IN and SBN from experimental study

Crude Oil Insolubility Number (IN) Solubility Number (SBN)Crude A 4.5 25Crude B 36 76Crude C 29 51Crude D 39 63

26 Ju ne 2009


Compatibility Study of Crude A and Crude B Blend

Compat ibi l i ty studies were car-ried out with Crude A and Crude B blends in various proportions as shown in Fig 2 (a). It was observed that blending of Crude A with Crude B decreases the SBN of composite blends up to the IN of Crude B and further the IN was found to be greater than the SBN of composite blends. It was found that the calculated SBN of Crude A ( 25), which is less than the IN of Crude B (36), hence the compatible blend composition range predicted was up to 78 ( % vol.) of Crude A. The remaining of the blend proportions was incom-patible due to higher IN with respect to SBN of composite blends. It was found that the experimental data

been reported. That attributed to separation of asphaltenes from the petroleum solution or blend. There-fore blends should be prepared in the order where SBN of composite blends decreases to mitigate the separation of asphaltenes.

The theoretical model blends data were compared with the obtained CII values. The CII criteria covered a large scale under uncertainty region (0.7 – 0.9) e.g., compatible range was only up to 52 (% vol.) of Crude A mixed with Crude B. The obtained CII value for the stated blend was 0.7, where uncertainty in blending was up to 0.9. However, the SBN parameter predication indicates the compatible blend specifically up to 78 (% vol.) of Crude A mixed with Crude B [Fig 2 (b)]. This implies that the IN and SBN parameter prediction provides better understanding of demarcation between compatible and incompat-ible crude blends. The experimental study (IN and SBN) and theoretical prediction has shown a good accord with the reported work.

The phenomenon of incompatibility is also explained on the basis of SARA compositions. At higher per-centages of Crude A, in composite blend of Crude A and Crude B, the amount of saturates increased com-pared to the asphaltenes content. Thus, it leads to more de-stabilized asphaltenes in the composite blend. Eventually, it results the flocculation / precipitation of asphaltenes and the composite blend turned into incompatible.

Fig. 2 (a) Experimental data Vs Theoretical model prediction for Crude A-Crude B blend

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Ju ne 2009 27


Compatibility Study of Crude A and Crude C Blend

Crude A and Crude C crude oil blend compositions were investigated in various proportions in the similar fashion [Fig 3 (a)]. It was found that the SBN (25) of Crude A was less than the IN (36) of Crude C, hence the crude oil blends would not be compatible in all the proportions. Therefore crude oil blends were prepared in such a manner where the SBN of the blends decreased and compatible up to the IN of Crude C. It was found that the blend is compatible up to 83 (% vol.) of Crude A. The remaining blends were incompatible due to increment in IN compared to SBN of blends. The experimental data converged to the result obtained from theoretical model blends of the crude oil as shown in Figure 3 (a).

As discussed erstwhile, the Crude A-Crude B blend follows the CII criteria scale which covers the large blend composition and it was only up to 61 (% vol.) of Crude A with Crude A-Crude C blend. SBN parameter predication indicates the compatible blend composition up to 83 (% vol.)

of Crude A with Crude C, as shown in [Fig 3 (b)]. IN and SBN parameter render to predict the compatible and incompatible crude blend composi-tions. This study also provides good agreement between experimental and predicted compatibility by theoretical model parameters.

Compatibility Study of Crude A and Crude D Blend

Crude A and Crude D crude oil blend compositions were also investigated in various proportions in the similar fashion [Fig 4 (a)]. Again It was found that the SBN (25) of Crude A was less than the IN (39) of Crude D, hence the crude oil blends were not be compat-ible in all the proportions. Therefore crude oil blends were prepared in such a manner where the SBN of the blends decreased and compatible up to the IN of Crude D. It was found that the blend is compatible up to 64 (% vol.) of Crude A. The remaining blends were incompatible due to increment in IN compared to SBN of blends. The experimental data converged to the result obtained from theoretical model blends of the crude oil as shown in Figure 4 (a).

Conclusions

The prospect of processing opportune crude oils opens the new window for the refiners to bring flexibility in the processes/ operations. The prediction from IN and SBN are useful information for crude oil blend compatibility. From the present study the following conclusions can be drawn

I ■ N increases with % vol. of as-phaltenes contentI ■ N was maximum and minimum for Crude D and Crude A crude oils respectively. Higher composition of Crude A (up ■to 83 % vol. with Crude C) is used to get the compatible blend and conversely, the lower composition is used with Crude D (up to 64 % vol. with Crude A). Blend compositions should always ■be made in such a manner that the SBN decreases for their respective blends. Hence, blending approach is also important, to reduce the con-centration and avoid the precipitation of asphaltenes from the blends. I ■ N and SBN parameter predicts 20 % extra blend composition w.r.t. CII prediction. Therefore, IN and SBN pa-rameter provides much perceptive

Fig. 3 (a) Experimental data Vs Theoretical model prediction for Crude A-Crude C blend

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and precise results for compatible and incompatible crude oil blend compositions compared to CII un-certain region.

In future, determination of compat-ibility parameters can be covered with non-asphaltenic crude oils and various processed oil streams.

Acknowledgement

The authors gratefully acknowledge Dr. M. A. Siddiqui, ED (R&D) and BPCL management for their constant support and encouragement to accomplish this work.

ReferencesMurphy, G.; Campbell, J. Fouling ■Mechanisms. 1992, 249-261Speight JG. J Petrol Sci Eng 1999, ■22, 3–15Fan T; Wang JX; Buckley JS. SPE/■DOE IOR Symposium, Tulsa, 2002 Wiehe, I. A.; Liang, K. S. Fluid Phase ■Equilib. 1996, 117, 201- 210.Pfeiffer, J. P.; Saul, R. N. J. J. Phys. ■Chem. 1940, 44, 139-145.Dickakian, G. B. and Seay, S., Oil ■and Gas Journal 1988, 86, 47-50Mason G. U.S. Patent 6,839,137 ■B2, 2005.

Fig. 4(a) Experimental data Vs Theoretical model prediction for Crude A- Crude D blend

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Irwin A. Wiehe, J. Disp. ■Sci. and Tech. 2004, 14, 333-339Irwin A. Wiehe*,† and Ray-■mond J. Kennedy, Energy & Fuels 2000, 14, 56-59Wiehe, I. A.; Kennedy, R. J.; ■Dickakian, G. Energy Fuels 2001, 15, 1057-1058.Buckley, J. S. Fuel Sci. ■Technol. Int. 1996, 14, 55-74.Buckley, J. S. Energy Fuels ■1999, 13, 328-332.Griffith, M. G.; Sigmund, C. ■W. In Marine Fuels; Jones, C. H., Ed.; ASTM, Philadel-phia, 1985, 239-245.Gaeste; C.; Smadja, R.; ■Lamminan, K Rev. Gen.des Routes et Aerodromes, 1971, 85, 466Asomaning, S.; Watkinson, ■A.P; In: Bott; T.R., Melo, L.F., Panchal, C.B., Som-erscales, E.F. eds. Under-standing Heat Exchanger Fouling and its Mitigation, New York; Begell House, 283, 1999.Asomaning, S., Petroleum ■Science and Technology 2003, 21, 3&4, 581-590

Ju ne 2009 29


Sustainability and Sustainability ReportingSatish Chand and Shantanu DasguptaONGC

Abstract

Sustainable development is gaining increasing importance in the light of global warming. However, some perti-nent issues related to sustainability and sustainable development still remain a topic of global discussion. The issues are chiefly related to the time span, pro-cesses, responsibility etc . This article is an attempt to address all these issues in the most acceptable and pragmatic form. Further, the article deals with sus-tainability reporting which is increasingly being considered important to enhance transparency in reporting and improve stakeholder’s confidence.

Introduction to sustainability

A common definition

In common parlance, ‘to sustain’ is simply to maintain undiminished over time. In this elementary sense, it is not clear that sustainability is always a desir-able goal or attribute –oppressive social structures such as casteism or dicta-torships surely need not be sustained. Hence, when talking about sustainabil-ity, it is essential that one clarify what one is trying to sustain. Most usages of sustainability are in or have emerged from the environmental context. Indeed, sustainability has almost replaced or be-come synonymous with ‘environmental soundness’ amongst activists, analysts and policy-makers alike. ‘Sustainability science’ is the new buzzword amongst environmental scientists abroad.

The concept of sustainability emerged in the mid-20th century as a fairly straight-forward notion in the management of renewable natural resources such as forests and fisheries. In this narrower context, the term simply meant extract-ing from a resource stock at a rate below the stock’s natural growth rate.

Today, Sustainability has become a complex term that can be applied to almost every facet of life on Earth, par-

ticularly the many different levels. Biologically (wetlands, prairies and forests) this means avoiding extinction, and living to survive and reproduce. Socially, human organization concepts (ecovillages, eco-municipalities, sustainable cities), it means avoid-ing major disruptions and collapses, hedging against instabilities and dis-continuities. Economically, it means undisrupted growth, albeit slow without adversely affecting other economic parameters like sustainable agriculture, sustainable architecture and renewable and non renewable energy. Thus a com-mon definition of sustainability may be “A sustainable system is one which survives or persists.”

Time span and sustainability

However, what often pass as defini-tions of sustainability are therefore usually really predictions of actions taken today that one hopes will lead to sustainability. For example, keep-ing harvest rates of a resource system below rates of natural renewal should, one could argue, lead to a sustainable extraction system—but that is a predic-tion, not a definition. When one says a system has achieved sustainability, one does not mean an infinite lifespan, but rather a lifespan that is consistent with its time and space. We expect a cell in an organism to have a relatively short lifespan, the organism to have a longer lifespan, the species to have an even longer lifespan, and the planet to have a still longer lifespan. But no system (even the universe itself in the extreme case) is expected to have an infinite lifespan. A sustainable system in this context is thus one that attains its full expected lifespan without ma-jor disruption. Thus a more qualified definition should include the time span , sustainability thus is defined as “A system is sustainable if and only if it persists in nominal behavioural states as long as or longer than its expected natural longevity or existence time;

Shantanu Dasgupta, Chief Chemist, ONGC is working with the Carbon Management Group. Shantanu has 19

years professional experience in ONGC in different areas: drilling, production and processing, R&D on processing, training institute, and carbon management. A gold medalist from Ranchi University and a KS Krishnan DAE research scholar, Shantanu has also done his PG Diploma on Ecology& Environment and Masters in Business Administration. He has published several papers in national and international journals.

Dr Satish Chand, Deputy General Manager (Chemistry) ONGC is working with the Carbon Management

Group. Dr Chand has 29 years professional experience in ONGC in different areas: drilling, production and processing, R&D on processing, , and carbon management. Dr Satish Chand has done his PhD on “Physico chemical properties of surfactants and their role in micro emulsion” from South Gujarat University, Surat.

30 Ju ne 2009


and neither component- nor system-level sustainability, as assessed by the longevity criterion confers sustainability to the other level.” In a more practical way, “Sustainability is the term used to describe developments that meet the needs of today without compro-mising the ability to meet the needs of tomorrow.”

Sustainability in global perspective

Sustainability, as explained above, is the capacity to maintain a certain process or state indefinitely. An "un-sustainable situation" occurs when natural capital (the sum total of nature's resources) is used up faster than it can be replenished. Sustainability requires that human activity only uses nature's resources at a rate at which they can be replenished naturally.

Sustainability now focuses much of its attention on managing levels of con-sumption and resource impact by seek-ing, for example, to modify individual lifestyles, and to apply ideas like ethical consumerism, dematerialisation and decarbonisation, while at the same time exploring more environmentally friendly technology and methods through ecodesign and industrial ecology.

At present the developing world per capita consumption is sustainable (as a global average) but population numbers are increasing and individu-als are aspiring to high consumption Western lifestyles. The developed world population is stable (not increasing) but consumption levels are unsustain-able. The task is to curb and manage Western consumption while raising the standard of living of the developing world without increasing its resource use and environmental impact. This must be done by using strategies and technology that decouple economic growth from environmental damage and resource depletion.

Processes to achieve sustainability

Some important issues

If we know what sustainability is and why it should be achieved, then the answer to the ‘how’ question should

also be straightforward. At the level of an individual renewable resource, which is where the idea of sustainabil-ity originated, the problem did seem straightforward. But the problem is now complicated at the Non renewable resource at the wider scale when one talks about moving towards a sustain-able future. As always, the ‘how’ is in-tertwined with the ‘what’. Oil reservoirs are complex entities not simple bank balances that grow at fixed interest rates. Sustainable use requires ‘adap-tive management’. Focus ought to be not just on sustaining a particular level of production, but also on ensuring low variation in that level from year to year. Some scientists argue that the resource manager should focus on ‘sustainabil-ity as resilience’, i.e., the renewable or alternate source of energy. There is a raging debate as to whether reduc-ing variability in the short-term may actually contradict efforts to increase resilience for the long-run. Finally, there may be situations where conditions shift systematically rather than just fluctuate – as possibly the greenhouse effect might to do to our climate. Under these conditions, what may be required to ‘sustain’ production systems is not just stability or resilience but adaptabil-ity. This debate about which temporal attributes to focus on has enriched, as also complicated, the notion of sustain-ability. Few scientists have been able to translate these abstract notions of low variability, resilience or adaptability into concrete prescriptions for specific ecosystems.

Yet another issue arises from the interconnectedness; it is possible to point out that continuous increases in inter-connectedness at the global scale are not always desirable. Analysts of dynamic systems have shown that in highly interconnected systems, small structural perturbations may result in wild fluctuations. Such behaviour has already been observed in large, inter-connected power systems, leading to what is called ‘cascading blackout’. Remarkably similar behaviour has been noticed in international oil markets in recent times – crashes in one market triggering off fluctuations globally.

The notion of sustainability becomes much more complicated when we

transfer it to a higher level, be it liveli-hoods, economies or societies. If the discussion is about how to manage a particular oil reserve specifically as a source of energy, we can have a somewhat coherent discussion as to how it might be managed sustainably. But when the debate shifts to one of balancing environment, it becomes much more difficult to talk about sus-tainability. Over the past several thou-sand years, humankind has steadily replaced forests with agriculture, which seems to have sustained quite well and support many more human beings at the same or even higher level of well-being. What combination of forest and non-forest is then essential to maintain human well-being undiminished? More recently, industrial processes have been providing substitutes for many forest products and even for some agricultural products. Is the conver-sion of agricultural land into industrial estates then necessarily a sign of ‘un-sustainability’? Economists have been engaged in a bitter debate about the question of whether man-made capital such as industrial infrastructure can substitute for natural capital such as land. For instance, if the replacement of agricultural products by synthetic ones generates much greater greenhouse gas emissions (due to say fossil fuel use) it might be called more unsustain-able, otherwise not. Oil reserves, as producers of non-renewable materials, surely cannot be said to be promoting ecological sustainability? But does this then mean that all oil exploration and production activities from such re-serves everywhere should stop? Surely even primitive societies used some amount of stone and metal? So what level or type of use of non-renewable should be considered unsustainable? Again, the notion of sustainability of-fers only limited practical guidance. Indeed, some scholars have used the same argument even in the context of groundwater depletion. They argue that the mining of non-rechargeable aqui-fers – as is happening in many parts of India – may seem ‘unsustainable’. But if this groundwater mining represents a temporary phase whereby farmers generate high levels of cash income, educate their children and diversify their livelihood portfolios by getting into non-agricultural activities, as has

Ju ne 2009 31


happened in parts of Gujarat, then this substitution of natural capital with human-made capital should be accept-able. That mining of non-renewable aquifers often leads to lowering of re-newable aquifers makes this argument somewhat unconvincing, and when one considers the inequitable distribution of the gains from such mining one may choose to reject this approach altogether. Nevertheless, the argument serves to highlight the point that rigid notions of ‘sustainable groundwater use’ may be problematic when the entire world is engaged in the mining of all forms of non-renewable.

This brings us to the question of why, even in relatively simple situations, users continue to use resources unsustain-ably. The answers are diverse, if not di-vergent. At a superficial level, the debate is between those who point to the rapid and continuing increase in population levels and those who point towards enormously high consumption levels in developed countries. At a deeper level are the various possible explanations for continued high consumption, poverty and population growth.

Acceptable solutions

However, certain common threads seem to be emerging. If adaptive man-agement is going to be necessary, then this trial-and-error should obviously happen at a scale and in a manner that resource managers can relate to as also not spill over into too many ‘downstream’ impacts. Clearly, users (such as tribal communities in central India) who are in daily contact with the ecosystem and have been so for sev-eral hundred years should have a major role in such adaptive management, and this should be done at micro-levels rather than going in for one-solution-fits-all approaches.

Furthermore, the response of modern reductionist science to high environ-mental variability and complexity has been to control – GHG emissions by technologies like CO2 sequestration, clean coal, and low carbon. But many more inputs have to be imported.

Further, world over, there is a raging debate over the ecological and social

equity and finally it has been accepted that sustainability should be considered holistically involving social, ecological and economic sustainability together. Also it is now an almost accepted axiom post World Earth Summit that differentiated responsibility. Sustain-able development, in that light, is con-sidered an imperative.

Sustainability and the role of a corporate entity

No corporate entity can survive or sustain in an insulated environment. The input—process (system)—out-put—marketing—profit model of any corporate entity very clearly indicates that the corporate entity is absolutely dependent on the external environment for its sustenance and survival. Thus, it is the responsibility of all corporate en-tities to contribute effectively towards the sustainability through sustainable development model. This is imperative for the entity to ensure a sustainable growth for a longer period of time. If an oil production company exploits the entire reservoir within a very short time, not only will this damage the reservoir irreversibly( with less amount of total extracted oil) but will reflect a very poor planning as there will be no oil left to be extracted in future . Thus, optimisation and sustainable development of the reservoir is a must.

However, sustainable growth does not indicate economic growth alone, it has a broader social connotation which involves a holistic approach including ecological, financial and social growth in a sustainable manner thro’ the ac-tivities and involvement of a corporate. The relations of a corporate with these three parameters are briefly explained below.

Ecological

The corporate utilises natural resources for its operations. If these resources are used without a proper plan, the resourc-es will either be exhausted or polluted irreversibly. Besides, with the relation between global warming and unprec-edented increase in the GHG emission having been scientifically established by IPCC reports, there is a widespread concern about the rising GHG emission

in the atmosphere. Global, regional, national and local level protocols/laws have been framed to ensure ecological sustainability which all corporate needs to adhere to. The corporate must there-fore devise an ecologically sustainable model for its operations.

Social

All corporate entities function within a society. They draw the raw materials from the society, employ man power from the society and produce / market their products for/ to the society. Thus it can not remain insulated from the societal demands and expectations. In no circumstance can a corporate func-tion in a way that is detrimental to the greater societal well being or the general societal perception of equity as those functions would be unsustainable. Apart from the legal framework which the corporate are bound to follow, a good corporate always aims at contributing towards a sustainable social growth which will have a direct positive impact on its overall performance.

Financial

The importance of sustainable financial growth for a corporate can not be over emphasised. Corporate must have a fi-nancial growth which is the very reason of its existence. However, growth at any cost is no longer a tenable proposition. Corporate must have a sustainable financial growth policy for its long term existence.

As is evident, these three aspects of sustainable development are not in-sulated but are interlinked and taken together, gives rise to a holistic de-velopmental model, the sustainable development. The performance of a corporate , according to this model, is depicted through a holistic reporting—involving all three aspects of growth-- known as sustainable reporting. The performance of a corporate following sustainable development model of growth is evaluated on the basis of its sustainable report much in the same way as the financial performance gauged by the Annual report and bal-ance sheet. World over, there has been an increasing trend among major cor-porate entities to publish their sustain-

32 Ju ne 2009


ability reports, which in near future may become the acceptable norm replacing the annual report.

Sustainable report: Basic contents

A sustainable report will typically con-tain all the essential contents of an an-nual report like CEO’s message,, details of the business, mission and vision statements etc. Where it differs from the annual financial report is that while the latter analyses financial parameters of the reporting period against the Key performance indicators (KPI) related to financial performance, the former

analyses financial, social and environmental

performances against the respective KPIs for the reporting period. Thus Sus-tainable reporting is an improvement over the annual financial reporting, ca-tering to the sustainable development of a corporate.

Process involved

Sustainability reporting, it must be clear, is the reporting of the performance of a corporate in the field of sustainable development. This presupposes that the corporate must have a corporate policy on sustainable development with a triple bottom line approach. Further, the corporate must have derived some policy guidelines in financial, social and environmental sectors so that all the operations of the corporate follow these guidelines; i.e. the broad op-erational framework is suitably modi-fied to incorporate these guidelines. T h e performance of

each bottom line is measured in

terms of some “key performance indica-

tors (KPI)” which are decided at the highest level. In this regard, it is per-tinent to mention that Sustainable de-velopment has acquired an altogether new dimension in the wake of global warming and climate change. IPCC, in its 4th assessment Report has categori-cally stated that the world humanity must aim for sustainable development to stall the disaster associated with un-mitigated global warming. Thus, GHG accounting and carbon management by the corporate forms an essential part of the Sustainability report. The processes involved are:

Framing corporate policy and cor- ■porate guidelinesIncorporating corporate guidelines ■in the operational frameworkDeveloping KPIs ■Selection of base year ■Evaluating all operations in terms of ■these KPIsGHG accounting and identify scope ■of improvementEvaluating past implementation ■recordsSustainability report ■

Bringing out the initial sustainability report is a time consuming exercise which involves developing KPIs, first time evaluation of the performance at all facilities etc which demands a total involvement of Finance, HR, HSE, Car-bon Management and all the operating facilities of the corporate. However, subsequent reporting becomes easier and less time consuming.

Conclusion

The concept of sustainability and sus-tainable development are the present day imperatives. Corporate entities are fast realising the importance of adopt-ing sustainable development model, which is fast becoming a viable busi-ness model. Corporate sustainability reporting (CSR), till now is in nascent stage, at least in developing countries. But with each passing day, as the global protocols are getting stronger for mitigation of GHG emission, a time is not far off when CSR will replace the conventional annual reporting. It is therefore prudent to start the prepara-tion as early as possible.

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Award Winning PostersExploration model and hydrocarbon prospectivity of Middle Miocene S1 clastics (Tapti Formation) ■in Heera-Panna-Bassein Sector, Bombay Offshore Basin, India (A new play in known basin)Hydrogen production by direct decomposition of methane over supported ni- catalysts■Guerbet Esters: A New Class of Alternative Fuel■Surfactant based gel: a clean hydraulic fracturing fluid■Basics of bridging particle size selection – no more fine, medium, or coarse■

Abstract

The Middle Miocene clastic play, known as”S1 pay’ “is one of producing reservoirs in the Bombay High field. The occurrences of commercial gas in this pay located at the edge of Bombay high east fault in Well BHE-A, suggest the importance of this play east of the Bombay High field. There was thus a need to have a detailed evaluation of such a potential shallow target in the basin which has so far been probed exclusively over Bombay High field. Heera-Panna-Bassein Sector of Bombay Offshore Basin is one of the potential area to evaluate the Middle Miocene S1 sands prospectivity in order to accelerate the shallower reservoir exploration in the basin. The present work encompasses the integrated studies to evolve the exploration model for S1 pay for adjudging the upside potential of hydrocarbon for Middle Miocene clastic sequence in the area.There are rapid litho facies changes in S-1 interval which is composed of micaceous sandstone, siltstone and calcareous fossiliferous shale / claystone lithofacies in study area. Dominance of sandstone- siltstone facies over Bombay high and shale- silt facies in Heera- Panna- Bassein Sector is noticeable observation. In general average thickness of S-1 pay ranges from 20-24m having

Exploration model and hydrocarbon prospectivity of Middle Miocene S1 clastics (Tapti Formation) in Heera-Panna-Bassein Sector, Bombay Offshore Basin, India (A new play in known basin)Dhruvendra Singh, Dr. Bamdeo Tripathi, Dr. A M Chitrao, A A Sheikh K G Vijaylaxmi, Santanu Mukherjee, S Bhowmick, Rajiv Verma and P K BhowmickONGC

relatively lesser thickness over Bombay High in comparison to easterly lying area. It has also been observed that while sedimentary inputs, in general, is from north eastern direction, and major depositional centres are lying near BH-D, BH-35 and BHE-A well over Bombay High, towards south of Bombay High near WO-15/16, near B-157 C-1, B-147 and B-23 wells in Heera-Panna-Bassein sector. Structural features of the area during S1 pay top and major stratigraphic seismic horizons have been delineated. S1 pay has been deposited under broader tidal complex regime comprising tidal flat, tidal channel, meandering with point bar morphology in shallow marine depositional regime. These sediments were probably derived from destruction of proto Narmada Delta and transported in suspension mode. Facies association, sedimentary structures and textural characters of sandstone –siltstone facies are suggestive of moderate to good and at places excellent reservoir rock characteristics. A good sand development has been observed near BNP-1, SAA-1 wells area while good silt facies are noticed in vicinity of B-55 area. Seismic attributes analysis depicts the channel like features which were derived between

the window of S1 to H1C, S1+10ms & 10-30ms (20ms) below S1 Top. A high amplitude anomaly has been observed within S1 interval having about 5 sq.km areal extent in east of B-55 area. The faulted BNP nosal feature and orthogonally oriented meander belt, located further north, is expected to provide favorable entrapment condition for the high amplitude events observed in S1 interval. These features are of exploration significance.

Based on study, the two wells were drilled to test the exploration model and adjudge the hydrocarbon potentials for further delineation of S1 pays beyond Bombay High. Drilling has validated the exploration model and commercial presence of gas with condensate has been established in the Heera- Panna- Bassein Sector and opened up large area for exploration.

34 Ju ne 2009


Hydrogen production by direct decomposition of methane over supported Ni- catalystsK K Pant, Ashok Chejara and R P VermaIIT, New Delhi

Abstract

The catalytic decomposition of methane in to COX free hydrogen and carbon material was investigated in a fixed bed

tubular reactor at different operating conditions using Nickel based catalyst. These catalysts were prepared by wet impregnation technique over alumina, zeolite (HZSM-5) and SiO2 supports. The

Guerbet Esters: A New Class of Alternative FuelRavindra Kumar, Bhawana Srivastava, Suresh K. Puri, Rakesh Sarin, Deepak K. Tuli, Ravinder K. Malhotra and Anand Kumar Indian Oil Corporation Ltd

Abstract

Environmental problems coupled with depletion of fossil fuels and its very high cost in the international market prompted the scientists to look into synthetic fuels. Synthetic fuels have gained the importance as these have the possibility of structural variations at the molecular level. Fischer-

Tropsch synthesis has been explored to develop synthetic fuels. Biodiesel is also a synthetic fuel prepared from vegetable oils and reported to possess better combustion properties than conventional diesel, results in substantial reduction of Green House Gases (GHG). However, biodiesel is reported to possess poor low temperature properties due to saturated esters and poor oxidation

stability due to unsaturated esters. In order to improve the low temperature properties and oxidation stability, structural variation have been made by converting the fatty chain of biodiesel

into a ß-branched chain to improve the low temperature properties of biodiesel. These ß-branched esters are called Guerbet esters and these are fully saturated with branching at ß-position.

Guerbet reaction has been used for dimerization of alcohols and to introduce ß-branching in alkyl chain of primary alcohols. By using this condensation reaction, ß-branched primary alcohol of cabon-16 was prepared. This ß-branched primary alcohol upon oxidation was converted to their corresponding acids. This acid was reacted with alkyl alcohols to produce methyl, ethyl, isopropyl and butyl esters of ß-branched fatty acid. These esters and intermediates were characterized by NMR and IR spectroscopic analysis. Physico-chemical properties of these esters were evaluated with respect to diesel and biodiesel. Structure activity correlation of these esters will be presented.

catalysts have been characterized by surface area and pore volume analysis, X-ray diffraction patterns, scanning electron microscopy, and thermo gravimetric analysis. Experiments were carried out over the temperature range 600-8000C and effect of parameters such as catalysts (metals and supports), methane flow rates, partial pressures were investigated. The activity, selectivity and stability were dependent on the amount of Nickel, type of support as well as operating conditions. In addition to the high activity and stability for methane decomposition, there was no generation of carbon oxides which makes these catalysts suitable for the production of pure hydrogen for fuel cell.

Ju ne 2009 35


Introduction

Opportunity for performance improve-ment and reserve addition in existing basins is a product of intelligent think-ing and dynamic visualization of con-vincing exploration models. Though Exploration is high risk and high cost venture, it is essential and critical key to finding new hydrocarbons for more reserves. Bombay Offshore Basin, which is an important oil-producing province, accounts for major share of production in the country. In a mature basin such as Bombay Offshore, where the large, medium and small sized structural traps have mostly been visited, it is the stratigraphic and strati-structural pools which now form the major target of exploration. Extensions of some of the stratigraphic/ strati-structural plays which are relatively well explored in major fields can and sometimes do form important traps in the newer areas. The Middle Miocene clastic play, known as”S1 pay’ “is such potential target in the basin which has so far been probed exclusively over Bombay High region only. The discovery of commercial gas in this pay in Well BHE-A, located east of the Bombay high east fault, the presence eight meter gas column in a well in the Panna JV Block, and the possibility of development of sandstone-siltstone facies in Heera- Panna – Bassein Sec-tor necessitated a re-look of available data of eastward extension in Footwall side to adjudge the upside potential of S1 Pay.(Fig.1).The objective of the present paper is to understand the extension of S1 pay beyond Bombay High in the east and to construct an exploration model to evaluate the po-tential of the S1 sand by integrating the 3D Seismic, geological and other data, and identifying areas for future hydrocarbon accretion.

Exploration model and hydrocarbon prospectivity of Middle Miocene S1 clastics (Tapti Formation) in Heera-Panna-Bassein Sector, Bombay Offshore Basin, India (A new play in known basin)Dhruvendra Singh, Dr. Bamdeo Tripathi, Dr.A.M.Chitrao, A.A.Sheikh K.G.Vijaylaxmi,Santanu Mukherjee, S.Bhowmick, Rajiv Verma and P.K.BhowmickONGC

Tectonics and stratigraphy

The mega-tectonic set-up for the west-ern offshore and the adjoining onland basins have been discussed in much detail by S.K.Biswas (1987).The basin has evolved as a result of initial rifting and subsequent breakup of Madagas-car from the Indian sub-continent dur-ing the Upper Cretaceous. The major structural elements from east to west are the NNW-SSE to N-S oriented shel-fal horst graben complex on the inner and the outer shelf margins bordering the coast, the Kori-Comorin depres-sion, Kori-Komorin ridge, Laxmi basin and the Laxmi ridge. The Kori –Comorin depression and Kori -Comorin ridge is a complex series of anatomizing horsts and grabens trending NNW-SSE in the northern part (Mumbai Offshore) to N-S in the southern part (Kerala Konkan) of the margin.In addition to the shelfal horst-graben complex tectonics, the other mega-tectonics identified are, Neogene gravity tectonics (shelf – up-per slope extensional with mid and low-er slope translational and contractional toe thrusts), and the broadly NE-SW trending strike slip faults associated with inversion structures. The Bombay shallow water basin which is restricted the shelfal horst graben complex has six major tectono-sedimentary blocks -namely Tapti-daman, Diu, BH-DCS, Heera-Panna-Bassein, Ratnagiri and Shelf Margin blocks. The study area is confined to the BH-DCS and the Heera-Panna-Bassein blocks( Fig.1and 2).The generalized stratigraphy of the Basin is given in Fig.3a (Zutshi et al;1993) and S1 status in stratigraphic records is shown in Fig.3b.

Status of exploration

CFP (France) carried out the preliminary study of S1 sand in the year 1979. They

suggested that the unit had been de-posited in a regressive phase during the Miocene age. Rao and Talukar (1979) has indicated this pay as shoe string sand deposited above the wave base and transported by longshore current. Basu et.al (1982) opined that shallow-ing of sea during Middle Miocene with development of lagoonal and marginal marine deposition regime have resulted in the deposition of S1 pay. Kale et.al (1984) has done sedimentological evaluation and depicted shallow marine environment for S1 pay comprising a phase followed by regressive and again a transgressive phase under fluctuating and low energy conditions. They have attributed sand silt deposition to brief period of moderate energy associated with wave action and silt-shale deposi-tion as suspect on deposit. Mishra et. al (1984) suggested a tidal flat regime of sedimentation associated with tidal channels. Sharma et. al (IRS, 1987) studied S1 sequence for designing the technological scheme. They have pro-posed a depositional model consisting of tidal channel separated by inter-tidal areas and associated tidal deltas. The study carried out by Bhosale et al in Jan 1997 considered data from 450 wells where S1 unit had been encountered. The report deals with the reservoir facies identification, depositional environment and reservoir potential of S1 sand. A study was also carried out by B.L. Lo-har et al in March’ 1999. Most recently IRS in 2006 has again taken up the S1 sand evaluation and prepared a geo-cellular model and suggested upside of hydrocarbon volume. However all above studies were concentrated to Bombay High only and no regional model was prepared. Wells drilled beyond Bombay High have very poor data availability for S1 pays. Occurrence of hydrocar-bon in S1 pay over Bombay high is an established fact but hydrocarbon

36 Ju ne 2009


The main structural elements at S1 pay level from east to west are the Bombay High- a broad roughly NNE-SSW trend-ing domal feature intersected in the east by a North-South trending fault with down throw towards east, the B-19-Mukta-Panna-Bassein Platform, B-55 structure N-S trending Central Graben and the finally rising to the east the Eastern Homocline. Two sets of faults are seen. The older fault trend is in NNW-SSE to N-S direction, which are mainly tensional, whereas the other trend which is NE-SW has a strike slip component and are younger. (Fig.6).

Structure Map (Depth) At the Top of S1 Level

Most of the exploratory wells drilled over Bombay High and Mukta-Panna-Bassein sector have penetrated through S1 unit. The data of these wells, time and velocity of seismic volumes have been used to prepare structure con-tour map on top of S1 unit (Fig.7). The structural features of area remain same as described in time map of S1. The S1 is encountered at shallowest depth in well BS-H (-997m) over Panna Field and deepest at B-157C-A (-1480m).

Thickness distribution

The isochronopach map of S1: (H1C-S1) show that thickness of S1 unit increases towards BH-D and BH-2 over Bombay High, southwest of B-65-A and B-23 whereas it thins towards Panna field in east and over the peripheral part of Bombay High including B-15 area. The gross thickness map of S-1 prepared from well data indicates a thickness

variation of 16 m. (in well WI6-PA) to 32 m. (in well BH-52). Most of the wells show average thickness from 20-24m. The maps clearly bring out the depositional maxima, minima and major channel axis. It has also been observed that while sedi-mentary inputs , in general , is from north eastern direction, major depositional centers are lying near BH-D, BH-35 and BHE-A well over Bombay High, towards south of Bombay High near WO-15/16 , near B-157 C-A ,B-147 and B-23 wells in Heera-Panna-Bassein sector.( Fig.8)

The areas of good sand development are around wells BH-D, BH35, BHE-6 and S1-6-4 wells in south Bombay High, and BH-19, BH-4 in north Bombay High. Fine grained siltstone concentration was also observed in vicinity of BHE-B, B-19-G and WO-15/16 area. In Heera- Panna Bassein Sector, these sands are patchy in nature and are aligned to channels identi-fied through attributes mapping. A good sand development has been observed near BNP-X, SAA-A wells area while good silt facies are noticed in vicinity of B-55 area in general Heera-Panna- Bas-sein sector is characterized by domi-nance of siltstone concentration.

Geological section

One N-S Geological cross –sections ( Fig.9) passing through the northern part of the Heera-Panna Bassein sec-tor along the wells BS-I, BS-E, SAA-A, identified prospect RBNP-S1A, BNP-X, B-55-B, B-55-D, B-55-A and B- 14-B is prepared based on the well data and the structure maps prepared at different levels. The objective was to show the structural relationship of the different stratigraphic units and the relationship of the S1sand vis-à-vis the other units. In the N-S section, the Panna Formation thicken towards the Surat depression in north and thin on the Neelam Platform area. The Bas-sein Formation is thicker in north, and is restricted over the platform. The Middle Eocene is represented mainly by clastics in well B-14-B in north. Higher thickness of Panna and Bassein for-mation indicates the syn-sedimentary nature of Surat depression and Central graben. Uniform thickness of Oligo-Miocene formations over the area, indi-cates similar depositional pattern till the end of Tapti Formation. The thickness

occurrence beyond the structure was not documented. Recent drilling of well SAA-A in Panna JV, as well as the hydro-carbon occurrence in the well BHE-A, located east of the Bombay high east fault encouraged a re-look the data of Heera- Panna – Bassein Sector.

Results and Discussions

Lithological correlations

There is a lithological variation within S1 across the area. The thickness of this unit is less over Mukta field (B-57) in comparison to Panna field and Bombay High. The S1 is divided into two units namely, Upper and Lower Unit. The Lower Unit overlain to F-33 limestone marker consists mainly of shales and siltstone, and is deposited during transgressive phase under shal-low marine environment. The Upper Unit of S1 is deposited under Tidal flat and shallow marine environment during regressive period. It is underlain by the F-32 limestone marker. This unit mainly consists of fine grain sandstone, silt-stone, claystone and shales. The wells in the western part of profile over the Bombay High, shows well developed channels. The sands thickness in wells BH-35, BH-D and BHE-A ranges from 9 to 14m. In the well SAA-A in the Mukta JV area in the east has 8-9 meters of sand. The area around Mukta field this unit contains finer clastics.

Structural configurations

The 3D and the 2D seismic data have been used to derive the time structure and depth structures at seismic horizon corresponding to H1C and S-1top. The calibration line is given in fig.5 repre-senting the S1 pay and H1C.

Figure 1: Location map of the study area.

Figure 2 .Tectonic map of the western

offshore basin

Ju ne 2009 37


tune of regional depositional regime at the end of Early Miocene sedimenta-tion. These sediments are texturally mature. Majority of transportation is the product of suspension population with some inputs from saltation mode. Moderately sorted sandstone contain-ing excess of fines probably represents

deposition in transitional environment of tidal and inter distributary shore line regime. Presence of finer suspended particles and better sorting also re-vealed graded suspension under low energy conditions.

Seismic attributes like Average Ab-solute Amplitude, RMS Amplitude & Sweetness attributes, clearly depicts the channel like features and all these which were calculated between the win-dow of S1 to H1C, S1+10ms & 10-30ms (20ms) below S1 Top marker brings out two distinct channels like feature with low/moderate amplitude.( Fig. 10 and 11) The low amplitude may be inferred to be silty/ shaly facies. The sinuous element is less in up-dip part towards north-eastern part i.e. in southern part of Tapti-Daman is linear channel fea-ture, this further become E-W in B-157 area whereas, the sinuous element in middle part which is B- 55/B-157 area is relatively more and composed of moderate-amplitude-semi continuous/patchy. These features are inferred to be channel depicting meandering and point-bar characteristics especially in east of BNP area. In southern part these elements are low sinuous in character and less prominently seen. Bombay High is the area where no clear trends/pattern is discernible based on amplitude spread. Analysis of these attributes along with meaningful

Figure 3a:

Figure 3b: S1 Pay in stratigraphic records

of all these formations are almost same with little thickening towards north. The section shows uniform deposition of S-1 unit over the area.

Depositional model

The S1 pay is composed of micaceous quartz arenite, micaceous lithic arenite, siltstone silty shale and calcareous fos-siliferous shale / claystone lithofacies in study area. However dominance of sandstone- siltstone facies over Bombay high and shale- silt facies in Heera- Panna- Bassein Sector is noticeable observation. Besides, occasion occurrence of some very thin limestone bands towards Bombay High has also been observed. The associ-ated sedimentary structures are cross bedding, flaser bedding, a few ripple like structures and occasional bio-tur-bation. The basal shaly facies compris-ing highly fossiliferous smaller benthic and planktonic forms was deposited under 40-50 m of bathymetry followed by gradual shallowing of 30 m. However upper sandy facies was deposited un-der extremely shallow marine to parallel conditions in bathymetry range of 0-10 m as indicated by faunal suite .Gradual shallowing up of the bathymetry is in

Figure 4:

Figure 5:

38 Ju ne 2009


color-coding scheme and conceptual relationship between seismic facies and their potential associated geologic fill, the net-to gross environment has been interpreted to be channel sands associated with point-bars in broader Tidal complex regime. The thickness pattern together with amplitude spread/ attributes maps are indicative of short lived tidal delta deposition for S1 inter-val in some part of Bombay high.

Integrated approach of the present study has led to infer that the deposi-tion of S1 unit has taken place shal-low marine tidal complex regime with some inputs from transitional deltaic regime. These sediments were derived from destruction of proto Narmada Delta destruction and transported in

Figure 6

Figure 7: Structure map at S1 Top

subscription mode. The mean channel and linear channels of Heera-Panna-Bassein sector have witnessed both sandy and shaly deposition in axial part. Such linear channel in most of the Heera-Panna-Bassein sector have been filled with low amplitude

shale deposits whereas sinuosity of channel have the accumulation of sandy and silty facies deposition which have resulted high amplitude anomaly exploration and targeted for testing. Such deposits are also expected to attain better reservoir characteristics.

Figure 8a and b: Isochronopach and Isopach map of the S1 pay.

Ju ne 2009 39


Figure 9

Well SAA-A drilled on similar feature in Panna JV corroborates the obser-vations where hydrocarbon presence established on well logs. The paleo shore line is inferred along the Bom-bay High East fault. The main Bombay High remained a relatively higher topographic feature in comparison to Heera-Panna-Bassein sector as evidenced from Isochronopach and isopach map of L-III to H1C interval and S1 pay thickness maps. The Bom-bay High is breached at places through which tidal currents has formed a tidal delta type deposits near BH-D, BHE-A, BH-35 area in the south and near BH-4 area in the northern part. Sea has inundated the entire area with pulses of transgressive and regressive cycle over Bombay High. Possibility of oc-currence of lagoonal environment just east of Bombay High east fault has also been postulated as depositional maxima in north-east trends have been observed. Area to the west of Bombay High remained under higher bathymetry in shallow marine inner neritic regime and witnessed mainly shale deposition. Bombay High has experienced winnowing actions which has resulted the development of better reservoir facies over this High.

Petroleum system

Detailed work carried out by Pandey et.al. (2004), Prasad et.al. (2001), Pa-hari et.al. (2001), Mehrotra et.al. (2002) and Datta & Shivam (2003) along with various other reports of RGL, Mum-bai have been extensively utilized. In Heera-Panna-Bassein area, source rock studies indicate that shales de-posited in Central graben and other

depressional areas during Early Eo-cene (Panna Formation) contain fairly rich, Type III organic matter indicating effective source beds. These regional source rocks are also considered as feeding source for S1 pay accumula-tion.Since the reservoir is developed between L-II & L-III main limestone reservoir of Miocene at shallower depth, these sands which are mostly fine to very fine grained grading to silt is highly unconsolidated. Data indicate the moderate to good and at places excellent characteristics for S1 pay in study area

Conclusions

Dominance of sandstone- siltstone facies over Bombay high and shale- silt facies in Heera- Panna- Bassein Sector is noticeable observation for S1 pay. A good sand development has been observed near BNP-X, SAA-A wells area while good silt facies are noticed in vicinity of B-55 area. The

Figure 10: Average Absolute Amplitude normalized across different seismic volumes

showing the stream patterns and deposition over the Bombay High structure.

gross thickness varies from 16 m to 32 m. It has also been observed that while sedimentary inputs , in general , is from north eastern direction, major depositional centres are lying near BH-D,BH-35 and BHE-A well over Bombay High, towards south of Bombay High near WO-15/16 , near B-157 C-A ,B-147 and B-23 wells in Heera-Panna-Bassein sector. S1 pay has been deposited under broader tidal complex regime comprising tidal flat, tidal chan-nel, meandering with point bar mor-phology in shallow marine depositional regime. These sediments were derived from destruction of proto Narmada Delta destruction and transported in suspension mode. Facies association, sedimentary structures and textural characters of sandstone –siltstone facies are suggestive of moderate to good and at places excellent reservoir rock characteristics.

Seismic attributes analysis depicts the channel like features. The sinuous element is less in up-dip part towards north-eastern part i.e. in southern part of Tapti-Daman is linear channel feature, whereas, the sinuous element in middle part which is B-55/B-157 area is relatively more and composed of moderate-amplitude-semi continu-ous/patchy. These feature is inferred to be channel depicting meandering and point-bar characteristics espe-cially in east of BNP area. In southern part these elements are low sinuous in character and less prominently seen. Hydrocarbon generation from matured source beds occurred during the late Early Miocene period and is

40 Ju ne 2009


Figure 11: Model for S1 pay showing depositional pattern.

also in process of active generation till recent time. Migration of gas, prob-ably remigratory in nature, is primar-ily considered through fault system. Structural closures and, fault closures are main entrapment mechanism in the study area. A high amplitude anomaly has been observed within S1 interval having about 5 sq.km. areal extent in east of B-55 area. The faulted BNP nosal feature and orthogonally oriented meander belt, located further north, is expected to provide favorable entrapment condi-tion for the high amplitude events ob-served in S1 interval. These features are of exploration significance which have been tested through drilling and validated the model and proved to be hydrocarbon bearing.

Acknowledgements

Author express their sincere grati-tude to Shri D. K. Pande, Director (Exploration) ,ONGC for providing an opportunity to firm up the exploration plan for S1 pay in Bombay Offshore Basin. They express their sincere gratitude to Shri S.V. Rao, Executive Director - Basin Manager, Western Offshore Basin, Mumbai for extend-ing all possible facility and critical guidance. The team members derived inspiration and enthusiasm from Shri P. K. Bhowmick, the then GGM- Head,

Offshore Field Development, WOB during entire course of investiga-tion. His interactive guidance led to establishment of first consolidated exploration model for S1 pay explora-tion. They also extend their thanks to fellow colleagues for the assistance rendered by them during the course of study. Views expressed in the paper are those of the authors and neces-sarily not the organization to which they belong.

ReferencesBasu, D.N., Banerjee, A., Tamhane, ■D.M., 1982. “Facies Distribution and Petroleum Geology of Offshore Basin, INDIA”, Journal Petroleum Geologist p.p. 51-75.Bhosale J.S. et al 1997:Re-evaluation ■of S-1 sand reservoir, Bombay High Field ONGC unpublished reportBiswas, Dr.S.K., 1987. “Regional ■tectonic framework, structure and evolution of the western margin basins of India, Tectonophysics, 1987, 135, pp 305-327.C.F.P., France, 1979. “S-1 Reservoir ■Assessment” Unpublished CFP Report.Kale, P.G. et.al., 1984. “Sedimentol- ■ogy, Reservoir, Petrography, Petro-physical studies and Electrofacies Analysis of S-1 interval Bombay High”. Unpublished KDMIPE Report No.ID 0010.

Kumar,N; Senapati, R.B.; Bisht, B ■S, : Geocellular model for S1 sand of Bombay High Field Unpublished, IRS, ONGC ReportLohar, B.L. et al. 1999 : Develop- ■ment of S1 sand, Bombay High, Unpublished IRS, ONGC ReportMisra, P.C. Marathe, U.G., 1984 ■“S-1 sand Prospect, Bombay High Field”. Unpublished BRBC Report.Pati, P.B., Kamat, V.V., 1986. “Re- ■view of S-1 Sandstone, Bombay High Field” Unpublished BRBC Report.Rao, R.P., Talukdar, S.N., “Petro- ■leum Geology of Bombay High Field, India”. Giant Oil Fields of Decade 1968-1978, AAPG Memoir 30, p.p. 487-506.Shukla, S., Singh, S.D., Ray Satya- ■ki, Shyam, A. “Micropaleontological studies of S-1 sand unit interval in the Bombay High wells, BH-D, SC-5 and SP-5”. Unpublished BRBC Report No.BRBC/RGL/REP/17/95 dated 9.5.95.Zutshi, P.L., Sood, A., Mahapatra, ■P. Ramani, K.K.V., Dwivedi, A.K., Srivastava, H.C., 1993. “Lith-ostratigraphy of Indian Petrolifer-ous Basins Document-V, BOMBAY OFFSHORE BASIN”. Unpublished KDMIPE Document.

Ju ne 2009 41


Hydrogen production by direct decomposition of methane over supported Ni- catalysts K K Pant, Ashok Chejara and R P VermaIIT, New Delhi

Introduction

Concerns over the environment and depletion of fossil fuels led to the con-cepts of hydrogen energy system and hydrogen economy. It is considered a clean source of energy and its market demand is increasing steadily. It is gener-ally accepted that in the near to medium term hydrogen production will rely on fossil fuels, primarily natural gas. Pres-ently most of the hydrogen is produced by reforming of hydrocarbons. The most conventional method of hydrogen pro-duction steam reforming of methane, is highly endothermic process (63.3 kJ/mol H2) and large amounts of CO and CO2 are formed as co-products which have either to be further processed or to be re-moved following the complex steps The thermo catalytic decomposition of light hydrocarbons / methane into hydrogen and carbon has been studied in recent years as potentially clean energy source for hydrogen production, avoiding CO2 formation and generating valuable car-bon nanofibers (CNF) having potential for a number of applications.[1-5]. Methane decomposition is a moderately endo-thermic process (37.8 kJ/mol H2) and hydrogen is the only gas product, so no further separation and purification steps are needed. Therefore, this process is simple and energy efficient and provides real zero CO2 emission. The main chal-lenges in the production of hydrogen via the catalytic decomposition of methane are the thermodynamic limited conver-sions at relatively low temperatures (<7000C) and the short lifetime of metal / catalyst at higher temperatures. Methane molecules are not active, so non-catalytic decomposition reactions require high temperatures. The decomposition re-action can have high conversions on a metal catalyst in the range of much lower temperatures, but the catalyst particles are easily encapsulated and deactivated by the solid carbon produced.

The property of produced from catalytic decomposition of methane depends on the operating conditions and the type of catalyst used. Metal catalysts generally used for the methane decomposition are usually based on Ni, Cu, Co or Fe. [6-10]. Supported catalysts such as Ni/Al2O3 have moderate activities for hydrocarbon decomposition but they are not very stable. In a very recent study Cunha et al. [10] reported that Raney type catalysts are good catalysts for the decomposition of methane into hydrogen and filamentous carbon. In the present investigation Ni catalyst supported on different supports (Al2O3, ZSM-5 and SiO2) were prepared by impregnation method. The effect of op-eration conditions on activity selectivity and stability of these catalytic systems was studied.

Experimental Details

All the catalysts used in this study were prepared by wet impregnation method. A series of support materials such as .-alumina, silica and zeolite (H-ZSM-5) were used for impregnation of nickel (Ni) metal. The initial loading of Nickel on all the catalyst was kept 10 wt.%. The catalysts were dried at 110° C for 6 hours followed by calcinations at 550°C for 5 hours.

The textural properties (Surface area and pore volume) of the fresh and used catalyst were measured by N2 adsorption at -196°C in a micromerit-ics apparatus ASAP 2010. Studies of the homogeneity degree of dispersion, phases present in the fresh catalyst and the morphological appearance of the deposited carbon have been carried out in a scanning electron microscope and XRD patterns. The activity of these catalysts was tested by conducting experiments in a tubular fixed bed (SS 316) reactor. ( Length: 770 mm, outer

diameter 25 mm and inner diameter 19 mm). Prior to activity tests, all catalysts were subjected to a reduction treat-ment using a flow of pure hydrogen for 3 h at 5500C. Experiments were done at different flow rates of methane and different temperatures to study effects of W/FA0 and temperature on hydrogen production. The experimental conditions were as follows: T: 6000C -8000C, P: 1 atm., W/FA0 (Kg of catalyst.sec/mol. of methane): 45-269. run time : 1-10 h. The composition of outlet gas was measured with a gas chromatograph equipped with a thermal conductor detector.


The BET surface area and pore volume of all the catalysts are shown in Table 1. Impregnation of Ni on the support reduced the surface area of the catalyst due to coverage of metal. As can be seen from Table 1 Ni/Silica supported catalyst has the highest surface area among three catalysts prepared. The powder XRD patterns of the fresh catalysts calcined at 550°C revealed clearly the presence of NiO as the only nickel-containing phase detected in all samples. Results indicated that NiO in-teracts strongly with the inactive support through the formation of spinal phase NiAl2O4 at calcinations temperature higher than 6000C. Scanning electron micrograps of these catalysts revealed good dispersion of metal over zeolite and silica supports.

To investigate the effect of catalyst ex-periments were carried out at different flow rates of methane and at different temperatures. Experiments were done with three different catalysts; each catalyst had 10wt. % nickel with dif-ferent support. Effects of W/FA0 and temperature on hydrogen production was studied with all the three catalysts prepared. Hydrogen production and ef-

42 Ju ne 2009


Catalyst Support Surface Area (m2/g)

Catalyst Surface Area (m2/g)

Pore Volume(cm3/g)

Ni/y-Alumina 220 148 0.34Ni/(H-ZSM-5) 440 206 0.47Ni/Silica 500 238 0.55

Table 1: BET surface area and pore volume for catalysts

fects of reaction conditions on reaction were measured to find the most suitable catalyst for methane decomposition re-action. Ni-SiO2 catalyst has been found active compared to other catalysts; which is attributed to the strong and uniform interaction between Ni and SiO2. The influence of the support, the metal employed, the feedstock composition and the operating conditions have been assessed to optimize hydrogen produc-tion and deposited carbon properties. Supported catalysts have limited the conversion of methane due to the restricted space available around the metallic active sites, which limits the growth of carbon and prompts the rapid deactivation of the catalyst. At 7000C and W/FA0 134 kg.s./mol, the methane conversion was 9%, 24% and 31% re-spectively over Ni/Al2O3, Ni/ZSM-5 and Ni/SiO2 catalysts. The high activity for methane decomposition has been found over silica support which is ascribed to the fact that the growth of carbon is not impeded by the silica walls or the avail-able space around them. As discussed earlier at high reaction temperature NiO reacts strongly with the inactive alumina through the formation of spinel phase NiAl2O4 at temperature above 6000C and this phase can not be reduced under the conditions of the reactions. As Ni is the active phase in the catalytic decomposi-tion of methane reaction, it is important to determine the temperature of reduc-tion of different Ni compounds present in the calcined catalysts. During the TPR of the Ni catalyst two reduction zones were observed. The first one at around 4600C corresponded to the reduction of NiO and the second one at 7200C cor-responded to the reduction of NiAl2O4 phase. Figure 1 shows methane conver-sion as a function of W/FA0 over Ni/SiO2 catalyst. Methane conversion and hy-drogen yield increased continuously as the contact time increased in the range of experiments carried out. Methane conversion increased from 25% to 43% as W/FA0 increased from 67 to 268 kg. cat/mol/sec. High hydrogen yield (100* moles of H2 in product per mole of meth-

ane fed. up to 40% was obtained over this catalyst in the range of experiments carried out. For all the runs carried out hydrogen yield was approximately same as methane conversion. Experiments were conducted for 6 hour to study the effect of run time on catalyst deactiva-tion. The results of effect of temperature on methane conversion and hydrogen yield revealed that temperature has a significant role on methane conversion. Methane conversion increased from 28% to 41% when reactor temperature was raised from 6000C to 8000C.

Effect of run time has revealed that Ni/ HZSM-5 catalyst deactivates faster compared to Ni/SiO2 catalyst (Figure 2). Higher methane conversions (>40%) and lower deactivation rate was ob-tained with Ni/SiO2 catalysts at 1073 K compared to other catalysts studied in the present study. Ni/ZSM-5 catalyst deactivated significantly compared to Ni/Silica catalyst most probably due to higher acidity of the Zeolite support.

Results on methane decomposition on various Ni-supported catalysts, revealed that there was a strong dependence of the nature of the surface carbon and CO formation rates on the nature of the support. At high temperatures an

encapsulating type of graphitic carbon was observed on Ni/HZSM-5 whereas Ni/SiO2 showed the presence of a dif-ferent form of carbon, which resulted in a greater lifetime for the latter two and a very fast deactivation for the former. The carbidic form of carbon was pres-ent at low temperatures (450°C) but absent when higher temperatures were employed (>500°C) on all catalysts.

TGA analysis was used for determining the weight of carbon deposited on spent catalyst. Scanning electron micrograph of fresh catalysts indicated that disper-sion of NiO particles is uniform over zeolite surface, while some agglomera-tion took place over SiO2 surface. This indicates good dispersion of metal over zeolite and SiO2 supports. NiO particles size of the catalyst indicated good impregnation of Ni salt over catalyst support. SEM results of deactivated catalysts( Fig. 3 a & b) revealed that deposited carbon appears as uniform coatings. This uniform coating reduces the lifetime of the catalysts. No fila-mentous carbon was observed on the catalyst which could be probably due to low loading of Nickel.

The carbon produced during the de-composition were uniformly dispersed on the surface of the catalyst. Therefore Ni alone is not a good catalyst for the production of carbon nano fibres from methane decomposition. Probably a high loading of nickel is desired for the generation of carbon fibre. Thermo gravimetric analysis was carried out for

Figure 1: Effect of space time on Methane conversion as a function of W/FA0 over Ni/

SiO2 catalyst

0.00

5.00

10.00

15.00

20.00

25.00

30.00

35.00

40.00

45.00

50.00

0 50 100 150 200 250 300

W/FAo(Kg/mol/sec)

Met

han

e C

on

v.(%

)

Ju ne 2009 43


spent catalyst to calculated total amount of carbon deposited on spent catalyst. By TGA analysis carbon content was 1wt% and 1.8 wt.% on the Ni/Zeolite and Ni/SiO2 catalyst respectively.

Conclusions

Ni/Zeolite and Ni/SiO2 are promising catalysts for the hydrogen production from catalytic decomposition of meth-ane in temperature range 600°C-800°C and give good methane conversion. Ni/SiO2 catalyst has been found bet-ter catalyst than Ni/Zeolite catalyst as it maintain its activity for methane decomposition reaction for longer pe-riod and produce hydrogen with good conversion of methane. It has been seen that nickel based catalysts are ef-fective catalysts for the decomposition of methane into hydrogen and carbon. The performance of these catalysts is due to the continuous supply of metal crystallites, which are detached from

Figure 2: Effect of run time on methane conversion over Ni/Zeolite and Ni/SiO2 catalysts.

Time vs Methane Conversion

0

5

10

15

20

25

30

35

40

45

0 1 2 3 4 5 6 7

Time(hrs)

Met

han

e C

on

vers

ion

(%)

Ni/Zeolite

Ni/Silica

the metal surface. The effect of pro-cess var iab les r e v e a l e d t h a t h igher contact time favors the stability and the activity is favored at h igher tem-perature. Higher concentration of methane resulted in reduced con-

version of methane. The high activity for methane decomposition has been found over silica supports with no pore structure and low surface areas. It has been found that the highest methane conversions and longest catalytic lifetime can be achieved with Ni/SiO2 catalysts at 1073 K. At higher meth-ane conversion no carbon produced in methane decomposition reaction, carbon is in the form of particles and the grains. These particles and grains are uniformly dispersed on the surface of the catalyst.

References Mari´a Jesu´s La´zaro, Yolanda Eche- ■goyen, Isabel Suelves, Jose´ Mari´a Palacios, Rafael Moliner, Decom-position of methane over Ni-SiO2 and Ni-Cu-SiO2 catalysts: Effect of catalyst preparation method, Applied Catalysis A: General 329 (2007) 22–29. M.A. Ermakova, D.Yu. Ermakov, Ni/ ■

SiO2 and Fe/SiO2 catalysts for pro-duction of hydrogen and filamentous carbon via methane decomposition, Catal. Today 77 (2002) 225–235. M. A. Ermakova, 1 D. Yu. Ermakov, ■G. G. Kuvshinov, and L. M. Plyasova, New Nickel Catalysts for the Forma-tion of Filamentous Carbon in the Reaction of Methane Decomposi-tion, Journal of Catalysis 187, 77–84 (1999) M.A. Ermakova_, D.Yu. Ermakov, ■G.G. Kuvshinov, Effective catalysts for direct cracking of methane to produce hydrogen and filamentous carbon, Applied Catalysis A: General 201 (2000) 61–70 I. Suelves, M.J. Lázaro, R. Mo- ■liner, B.M. Corbella, J.M. Palacios, Hydrogen production by thermo catalytic decomposition of methane on Ni-based catalysts: influence of operating conditions on catalyst deactivation and carbon charac-teristics, International Journal of Hydrogen Energy 30 (2005) 1555 – 1567. J.W.C. Liberatori, R.U. Ribeiro, ■D. Zanchet, F.B. Noronha, J.M.C. Bueno, Steam reforming of ethanol on supported nickel catalysts, Ap-plied Catalysis A: General 327 (2007) 197–204 J. Ashok, S. Naveen Kumar, A. ■Venugopal, V. Durga Kumari, M. Subrahmanyam, COX-free H2 pro-duction via catalytic decomposition of CH4 over Ni supported on zeolite catalysts, Journal of Power Sources 164 (2007) 809–814 A. Venugopal, S. Naveen Kumar, ■J. Ashok, D. Hari Prasad, V. Durga Kumari, K.B.S. Prasad, M. Subrahmanyam, ■Hydrogen production by catalytic decomposition of methane overNi/SiO2, International Journal of Hydro-gen Energy 32 (2007) 1782 – 1788. Jiuling Chen, Yuanhua Qiao, Yong- ■dan Li, Promoting effects of doping ZnO into coprecipitated Ni-Al2O3 catalyst on methane decomposition to hydrogen and carbon nanofibers, Applied Catalysis A: General 337 (2008) 148–154 Cunha A.F., Orfao J.J.M; Figueiredo ■J.L. Catalytic decomposition of methane on Raney type catalysts. Applied Catalysis A :General 348 (2008) 103-112.

Figure 3 (a)SEM micrograph of Ni/Zeolite spent catalyst (b) SEM

micrograph of fresh catalyst Ni/SiO2.

44 Ju ne 2009


Introduction:

Hydraulic fracturing is a technique that aims to increase well productivity by injecting a fracturing fluid at high pressure and flow rate sufficient to overcome the overburden stress and initiate a fracture in the formation. The high pressure produces new crevices in the rocks and widens the existing ones. These crevices, connecting with others, become conductors for oil and gas from more remote productive parts of the formation.

For the last three decades, polymer gels have been used as fracturing fluids either in linear or cross-linked state [Lulo et.al., 2001]. However, the high viscosity fracturing gel should break into a low-viscosity fluid after the frac-turing is completed. The breaker helps in cleaning the formation by allowing rapid counter flow of fluids to the sur-face. Conventional breakers are added in polymer based gels to clean the for-mation after hydraulic fracturing. But, most of the cases a part of volume of highly viscous gel occupies the created fracture and reduces the formation con-

Surfactant based gel: a clean hydraulic fracturing fluidKeka Ojha, Ajay MandalDeptt. of Petroleum Engineering

V ReddyManagement Trainee, IOCL

ductivity to a large extent. As a result, oil movement is restricted badly and the objective of hydraulic fracturing is not fulfilled. Proper cleaning of formations after hydraulic fracturing thus becomes a headache to the oil producers and the researchers.

A new fracturing fluid category, the sur-factant-based one, has been reported to reduce the formation damage [Sam-ual et al., 1999 & Samuel, 2006, Mait-land, 2000], without requirement of gel breakers and oil or gas produced can act as breakers for surfactant based gels. The main advantage of these solutions, compared to conventional polymer systems, is the potential for reduced formation and proppant pack damage. However, there are many other advantages. These fluids exhibit unex-pectedly low high-shear-viscosities re-sulting in low friction pressures, even in small tubular, require no additive. In ad-dition, due to the very low viscosity of the broken fluid, faster load recovery of injected fluids is possible. A final benefit offered by these systems is operational simplicity at the well site, since there is no need to “pre-gel” tanks ahead of the

treatment [Hunter, 1992].

The present work is accomplished with the purpose of evaluating a new surfactant based gel. Gel was synthesized using a commercial an-ionic surfactant, a vegetable oil as the organic phase and water. A co-surfactant was added to stabi-lize the gel. Rheo-logical tests were

carried out to evaluate the surfactant based gel (SBG) synthesized at vari-ous fabrication conditions. Break test conducted with the SBG showed its breaking capability in contact with in-situ oil and water.

Materials and Method

Synthesis of SBG

To prepare a surfactant based gel sev-eral anionic surfactants were selected as anionic systems are water wet, economical and less toxic compared to cationic ones and are therefore considered to be more eco-friendly and economic. On that basis sodium lauryl sulfate (SDS) and Na-salt of Dodecyl Benzoic Sulfonic acid as the surfactant were used for the present work. However, SDS is mainly used in the present work as it showed better efficiency than the other one. Generally alcohols and amides are added to the surfactant as cosurfactant to increase the stability of surfactant based gels. For the present work, Iso-amyl alcohol is selected, which will be compared with other co-surfactants in future. Pine oil and distilled water were used as the organic and aqueous phases respectively.

To prepare the surfactant-based gel, it was necessary to determine the gel region in the pseudoternary phase diagram [Varade et al., 2007]. The pseudoternary phase diagram was con-structed by plotting the percentages of water, oil, and surfactant/co-surfactant phases used in each experiment. By varying the chemical composition of the gel a pseudo ternary phase diagram was prepared within which gel region was identified. Gels were prepared in a 500 ml glass beaker with the help of a magnetic stirrer where water, oil, co-surfactant were added at the same time

Figure 1: Pseudoternary Phase Diagram

Ju ne 2009 45


and surfactant was added slowly while stirring otherwise it may form lumps in the gel. And it was stirred for 45 min by keeping the stirrer speed at 600 rpm. The synthesis temperatures were varied within a range of 30ºC to 70ºC. Co-surfactant to surfactant to ratio (C/S) was kept constant at 0.5 in the present study. A pseudoternary phase diagram is shown in the Figure 1. Rheo-logical test of the prepared gels were conducted in Physica Rheometer.

Break test

The gel break test was carried out in a sand pack system. The system consists of a cylindrical core holder of dimensions 3cm OD and 30cm length. The core holder is connected to a container followed by a displace-ment pump in the upstream. Initially the sand was collected and then it was sieved to get uniform size of 0.5625 mm for preparing the sand pack. First the core holder was cleaned, dried and then it was filled with the sand and the continuous ramming action of the sand was going on while packing. The sand pack was also saturated with the brine while packing. Rheological experi-ments for the collected samples were performed in a Brookfield rheometer. The purpose of this experiment was to demonstrate that the gel break oc-curs due to contact with oil and brine found in the sand pack, regardless of the period of time taken to perform the break test.


Rheological measurements of all the gels prepared were carried out in Physica US 200 rheometer. In order to check the viscoelastic behavior of SBG, rheological tests were carried out by varying the shear rate up to 500 /sec.

Variation of SBG Viscosity with Shear Rate

Figure 2 describes the variation of gel viscosity as a function of surfactant-cosurfactant (C/S) concentration and shear rate. It can be observed that with increase in the shear rate, viscosity de-creases at all C/S concentrations. But this decrease is more pronounced in the case of lower surfactant concentra-

tions. The higher surfactant concentra-tions gels are more resistive to higher shear rates.

This non-Newtonian flow response and corresponding increase in viscosity with C/S concentration is attributable to the dispersed fraction of micelles in the solution and the structure forming interactions between the aggregates and nature of micelle aggregates. And also at higher concentration of C/S, the spherical micelles will grow and en-tangle to form long flexible micelles.

The results are suggesting that for lower shear rates we can use the c/s concentrations up to 30% to get good viscosity. But for higher shear rates, the c/s concentration above 30% to makes the gel more shear resistant.

Variation of SBG viscosity with the pH

Effect of pH of solution on SBG rheol-ogy was tested by adding KCl con-centration of the solution. The results are plotted in the Figure 3. From both the graphs it can be observed that at

Figure 2: Variation of SBG Viscosity with Shear Rate at different C/S concentrations,

Synthesis temp=70ºC, pH=8.5.

Figure 3 : Variation of SBG Viscosity with Shear Rate at different pH values at different

C/S concentrations

46 Ju ne 2009


structures.

These results are sug-gest ing that at higher temperature and at higher concentrations of c/s the micelles are likely to form entangled worm-like mi-celles and become more robust for higher shear rates. Moreover, at higher temperatures the micelles were more structured and possess larger volume due to the increase in the sur-factant-water interaction.

Identification of Fluid Flow behavior

In order to identify the fluid behavior of the surfactant based gel, a plot between shear stress and shear rate was drawn as shown in figure 5. It is observed from the shear stress vs. shear rate curve that the curve is concave downward at low shear but became nearly linear at high shear, which is the basic property of the typical pseudoplastic fluid. Using power law model, flow consistency index (k)

and behavior index were determined. The results are shown in table 1.

Break Test

The break capacity of synthesized gel (SBG) in contact with oil or formation water was examined using gel break test. The results were verified by de-termining the viscosity of the collected samples, after flooding the gel into the sand pack saturated with residual oil and brine. This experiment was conducted a sand pack was prepared with 0.125mm sand by mixing the sand with brine(2% KCl) and prepar-ing a tight pack. It has been observed from the figure 6 that viscosity of the SBG is reduced to below 1cP when comes in contact with oil in the sand pack. The experiments proved that the synthesized gel breaks into very low

viscous liquid without addition of any additional breakers.

Conclusion

In the present study, a new sur-factant based gel (SBG) was syn-thesized and rheological behaviors were studied. The propert ies of SBG were observed to change with the concentration of constituents, pH, and fabrication temperature. The viscosity of the gel was found to increase with the co-surfactant/

Figure 4: Variation of viscosity with synthesis temperature

higher C/S concentration and at higher pH value the SBG is more resistive to higher shear stresses at higher shear rates. This can be attributed to the reason that at increased pH value all the micelles will be aligned in one particular direction to resist the shear stress more strongly. And also higher pH value makes the solution more vis-cous by eliminating the hydrogen ion in the solution. But this behavior was observed only up to pH value of 10 beyond which the gel was deteriorated. Hence, pH value was optimized at 9.5 and experiments were not carried out at pH higher than that.

Variation of SBG Viscosity with synthesis Temperature

The viscosity of miceller solutions are strongly affected by the fabrication conditions. Rheometrical measure-ments were conducted at a constant measurement temperature 30ºC on different C/S concentrations, at dif-ferent fabrication temperature ranging from 30ºC to 70 ºC. All other fabrica-tion conditions were identical. Figure 4 shows the influence of the synthesis temperature on the viscosity of the solutions. The viscosity increases with increasing synthesis temperature. Increasing the synthesis temperature enhances the thermal mobility of the micelles, leading to the formation of other temperature dependant miceller

Figure 5 : Shear Stress variation with the Shear Rate

C/S concentration Wt % Flow Behavior Index (n) Flow consistency Index (k)

27 0.14-0.88 6.56-19.6830 0.068-0.236 4.37-10.4932 0.015-0.28 3.98-9.5134 0.068-0.25 2.59-6.50

Table1: Flow Behavior and Flow Consistency Index of the various SBG

Ju ne 2009 47


surfactant concentration. Lower c/s concentrations were not resisting shear stress at higher shear rates and hence showed less viscosity. Where as higher c/s concentration gels were resisting more shear stress at higher shear rates compared to the lower c/s concentrations. Simi-larly with increase in the preparation temperature the viscosity of SBG was increasing because in that condition micelles were organized in such a way to gain the viscosity at higher shear rates. With increase in the pH of the gel also, the viscosity of the SBG was increasing because

in the basic medium the formation of micelle would be maximized.

From the results it can be concluded that at higher c/s concentration, higher pH, higher temperature the forma-tion of micelles were maximized and became more robust to retain the vis-cosity even at very higher shear rates. Apart from the above characteristics the gel is also ecofriendly, economical and easy to mix on location it can be effectively used as a fracturing fluid in hydraulic fracturing. And finally as it is water-based gel, it will be soluble in oil and water. Thus it successfully breaks

Figure 6 : Viscosity of variation of gel with time during Break Test down after the proppants were placed and leaves little or no residue. The synthesized SBG thus may be used in field without any formation damage to the reservoir prior to fracturing.

Acknowledgement

This work was financially supported by CSIR, New Delhi, India (Proj. No.: 22(0425)/07/EMR-II, dated: 30.03.07)

ReferencesLullo D., Ahmed G. B, Rae P. A. ■L., Meli R. A, “Toward zero dam-age: new fluid points the way” SPE 69453, 1-8, 2001.Samuel M., SPE, Schlumberger ■well services, H.A. Nasr-EI-Din, Saudi Aramco, and M.Jermmali, SPE, Schlumbereger well services “Gelled Oil: New Chemistry Using Surfactants” SPE 97545.(2006).Maitland G. C., “Oil and Gas Pro- ■duction” Current Opinion in Colloid and interface Science, 5, 301-311, 2000.Hunter R.J, Introduction to Modern ■Colloid Science, Oxford University Press, New York, 1992 (Chapter 1)Samuel M.M., Card R.J., Nelson ■E.B., Brown J.E., Vinod P.S., Temple H.L., Qu Q., Fu D.K., SPE Drilling and Completion 14 (1999) 240.Varade D., Sharma, S. C., Aramoki ■K. “Viscoelastic Behavior of Surfac-tants Worm-Like Micellar Solution In The Presence Of Alkanolamide” Journal of interface and colloidal science 313(2007) 680-685.

48 Ju ne 2009


Dr. Pranab Kumar Mukhopadhyay obtained the Bachelor of Chemical Engineering degree in 1955 from Jadavpur University, Kolkata and Ph.D. in Technology degree in 1964 from Gubkin Petroleum Institute, Moscow, Russia. He worked as a Chemical Engineer in the former Standard Vacuum Refinery (presently Hindustan Petroleum Refinery), Mumbai for five years (1955-60) and as Assistant Professor of Chemical Engineering at the Indian Institute of Technology, New Delhi for five years (1965-70). Dr. Mukhopadhyay was Head of R&D in Engineers India Ltd., New Delhi for fourteen years (1970-84) and Director (R&D), Indian Oil Corporation

for nine years (1984-93). Since 1993, he rendered consultation service to various organizations, such as Indian Institute of Petroleum, Dehradun, Petronas R&D, Malaysia, Bharat Petroleum Refinery, Mumbai, Central Pollution Control Board, New Delhi, etc. He was a Fellow of Indian Institute of Chemical Engineers and Indian National Academy of Engineering.

The Petrotech 2005 Lifetime Achievement Award was presented to Dr. Mukhopadhyay in recognition of his contribution to the Oil and Gas Industry in India.

We pray his soul rests in peace

R&D's Loss – Sad Demise

Time and time again reliance on com-monly held misconceptions of particle size requirements results in incorrect selection of lost circulation material, bridging material, subsequent formation damage, expensive remedial measures, and reduced production. A recent res-ervoir conference repeatedly presented descriptions of circulating losses when drilling reservoir rock with the acceptance of the need for expensive remediation. It was apparent from the discussions that very expensive remedial work is now ac-cepted as reasonable and necessary in some markets extremely sensitive to mud cost. Relatively modest additional mud costs which would prevent formation damage are routinely exchanged for 5 to 10 times that cost in remedial reservoir work in some markets.

For nearly 15 years much has been pub-lished on prevention of damage to res-ervoir rock, but those recommendations continue to be misunderstood or ignored by mud companies and drilling engineers alike. In many cases losses and damage to a reservoir are not related to the chem-

Basics of bridging particle size selection – no more fine, medium, or coarse Robert P. Schlemmer, Yon Azwa Sazali Scomi Oiltools Inc.

istry of drilling fluid used but are primarily dependent upon the correct selection of bridging material. Preventable reservoir damage occurs often because of:

Operational problems such as plug- ■ging of shakers results in delay of or mis-application of correctly sized bridging material Over concern for wastage of rela- ■tively inexpensive bridging material Misguided worry about formation ■damage by the material itself Unbridged induced fractures can ■damage reservoir beyond perforat-ing depth Production screen damage concern ■may drive selection of improperly sized bridging material necessary to protect a productive reservoir Particle size selection is too often ■based upon misunderstanding of non-standard terms "fine", "me-dium", and "coarse" Standard tests are misapplied ■There continues to be a lack of un- ■derstanding of particle size, form, hardness, and chemistry of bridging materials

A modified Permeability Plugging Test procedure has been designed which economically compares effectiveness of bridging materials, measures forma-tion lift off pressure, and can compare screen clearance by mud solids. When information gained from the test is ra-tionally applied, mud losses and screen failure can be eliminated, and produc-tion gained without damage to nearby wells while minimizing expensive reme-dial cleanup techniques.

This paper seeks to reinforce the reintroduce the need for product quality control and good engineering practices. It describes novel laboratory techniques, an effective and improved bridging material option for water based muds, and reviews accepted particle sizing considerations. It defines a simple and systematic ap-proach to interpretation of pertinent reservoir data, particle size selection for economical bridging, and presents actual well data demonstrating the ef-fectiveness of that rational design.

Ju ne 2009 49


Bahrain plans to spend $20 billion on its oil and gas industry over the next 20 years. Photograph: Getty Images Bahrain plans to invest more than $20 billion to modernise its hydrocarbons industry over the next 20 years, the oil and gas affairs minister said in comments published on Wednesday. Abdul Hussain bin Ali Mirza, also chairman of the National Oil and Gas Authority (NOGA), said Gulf island kingdom would spend $15 billion to develop and modernise

its declining Awali oilfield and $5 billion on modernising its only refinery, Bahrain’s Gulf Daily News reported. Source: http://

business.maktoob.

com/20090000004046/

Bahrain_to_spend_$20_

bln_on_oil_ industry/

Article.htm, May 27, 2009

Bahrain to spend $20 bln on oil industry

Hydrocarbon resources are finite and globally, people are now facing the challenge of finding new oil in difficult terrains. There is a need to change the way we find these new oil sources by using innovative solutions leveraging on high and advanced energy technology. Brunei has become one of the global technology leaders as it has produced world-class innovative solutions that fuelled the growth and sustained the development of its oil and gas industry. Brunei is recognised as pioneers of "smart technologies" which is to digitally monitor and control offshore operations efficiently from remote locations in real time. "Today, 70km offshore from here, and 8km under the seabed, valve settings are changed via computers, which adjust the flow of oil and gas to maximise production and optimise reserves". The Sultanate also leads breakthrough-drilling methods such as the snake-well drilling technique for complex conditions. There are a few operators that are currently exploring deepwater technology to increase the hydrocarbons production for the nation. "Brunei invests in these technologies as part of the sustainable development efforts, to sustain the oil and gas industry as well as to support the economic diversification efforts that the Brunei government is driving.Source: http://www.brunei-online.com/bb/wed/may27h4.htm,May27, 2009

Brunei a pioneer of smart technologies

50 Ju ne 2009

Journal of the petrotech societyJournal of the petrotech society

Techie News

R&D Conclave IIITheme “Commercialization of R&D : Issues & Challenges”

5th-7th March 2009 at GOA

A R&D from 5th-7th March 2009 at Goa. It was attended by 10 Professors/Sci-entists from reputed institutes/ Labs/universities and 58 Executives from Oil Industry. The Conclave was inaugurated by Mr Vikram Singh Mehta, Chairman, Shell India and Special Address was delivered by Mr M B Lal, Technical Member (P&NG), Appellate Tribunal for Electricity. The speakers were drawn from reputed Institutes like IIP, NCL, IIT and from Oil in-dustry like RIL, OIL, ONGC Institutes, BHEL, EIL IOCL R&D, Essar Oil, Mahindra & Mahindra, Shaw Energy & Chemicals Group, shell Technologies etc.

Ju ne 2009 51


Seminar on“Advances in Value Chain of Hydrocarbon Sector”

20th & 21st April 2009 at ChennaiThe seminar was conducted in collaboration with Chennai Petroleum Corporation Ltd on 20th & 21st April 2009 at Hotel Taj Connemara, Chennai. The programme was inaugurated jointly by Mr Anand Kumar, Director (R&D), IOCL & Mr K K Acharya, Managing Director, CPCL and was attended by 66 participants which included 32 from southern Academic Institutes and 34 Senior Executives from industry.

Academia Industry Interface Petrotech-2009 inaugurated by Dr Indira Samarasekera, President University Alberta, Canada

Besides the above a parallel session was held on the first day which was chaired by Prof M S Ananth, Director IIT (M) and was attended by Heads of Uni-versities of Southern India and Directors from the oil industry. The meeting deliberated on ways for bridging the gaps between Academia and Indsutry with respect to Course Curriculum and desired level of education/training as required by the industry.

Total no. of academia industry programmes organized

16

Total no of Students / faculty attended

950

Financial Assistance provided

Nearly 1 crore (by way of providing help to the participating faculty / students towards free boarding / lodging expenses)

The 15th Industry-Academia Interface seminar was organized on 13th-14th January 2009 at New Delhi during Petrotech-2009. 32 prestigious universalities/ institutes of repute participated in the event and held deliberations for two days. It was attended by 56 professors and 120 Students from academic institutions.

The Seminar was inaugurated by Dr Indira Samaraskera, President, University of Alberta, Canada.

An opportunity was given to students of each PETROTECH Chapter to make a 10 minutes presentation on the Conference theme “Energy Independence with Global Cooperation: Challenges & Solutions”. Best Chapters (one winner and two runner ups) were awarded with PETROTECH Trophy and cash prizes (winner ISM Dhanbad, Runner Ups (1) UPES, Dehradun, (2) MIT Pune)

52 Ju ne 2009


4th Summer School onPetroleum Refining & Petrochemicals

To share the advances made in the field of Petroleum Refining & Petro-

chemicals, technologies and to mutually gain from collective knowledge, experi-ence and practices at the national and international levels in the hydrocarbon industry. PETROTECH Society in col-laboration with IndianOil (R&D) and Indian Oil Institute of Petroleum Man-agement (IIPM) organized a 4th Sum-mer School Programme on Petroleum Refining & Petrochemicals from 1st to 6th June 2009 at IIPM Gurgaon. The participants were drawn from academia and technical institutions imparting education in multidisciplinary petroleum / petrochemical technology inclusive of chemical / mechanical engineering and related areas and practicing managers from BPCL, NRL, BRG, CPCL, IOCL etc. The summer school was attended by 58 participants (32 from technical institutes and 26 from the industry).

The 6 days seminar included topics on refining trends and challenges; world oil scenario & future of oil; challenges ahead; alternate fuels including hy-drogen, fuel quality & related issues;

crude oil characterization including S and High TAN crudes; petroleum pric-ing and economics: Indian & Global scenario; simulation & optimization of FCC; advancements in polyolefin catalyst; hydroprocessing; lube base stock; thermal cracking process; HSE; instrumentation & controls for refining & petrochemicals plants etc.

The Inaugural session was over presided by Mr V C Agrawal, Director (HR) IOCL and Mr Anand Kumar, Director (R&D) IOCL. Mr. Anand Kumar said due to the widening gap between the demand and supply, fast changing technologies, it has become more imperative to sit together and share the views and experi-ences to bridge the gap. In his speech he mentioned that deliberation of the 6 days summer school will come up with new ideas and innovations and how to review the curriculum in the institutes, so as to meet the requirement of industry.

Mr V C Agrawal in his inaugural speech appreciated PETROTECH Society for keeping the tradition of having a chemi-cal engineer honoured each year, who

has contributed a lot in different capaci-ties. In his speech he also mentioned certain important points to meet the challenges today in petroleum sector. He specified about the fuel quality, how to reduce the bottom of the barrel, energy conservation, fixing of plans for processing of more & more high sulphur crude and last but not the least how to make more money to help to meet the challenges in hydrocarbon sector.

Earlier Mr K K Gupta, ED IIPM wel-comed the august gathering and appreciated the initiative taken by PETROTECH Society for starting such a forum where industry and academia share their views and experiences for the benefit of the nation.

Mr J L Raina, Secretary General & CEO, PETROTECH proposed a vote of thanks to all present and informed all the future programmes of PETROTECH Society and strategies so that all may gain and contribute towards the drive to achieve self reliance in hydrocarbon and more towards goal of energy security and independence.

Ju ne 2009 53


Petrotech Society celebrated its 10th Foundation day on 9th June 2009 at Hotel Le Meridien, New Delhi. Many stalwarts and veterans of oil industry were present during the function. Ex-Chairmen, past Presidents and Secre-tary General of PETROTECH Society were felicitated on the occasion by

Petrotech Society celebrated its 10th Foundation day on 9th June 2009 at Hotel Le Meridien, New Delhi. Many stalwarts and veterans of oil industry were present during the function. Ex-Chairmen, past Presidents and Secre-tary General of PETROTECH Society were felicitated on the occasion by

the current Chairman, PETROTECH Society. In his opening remarks, he observed that the Society owes its pre-sentation to all the doyens of oil & gas Industry who have brought the Society to its present stature. Secretary General gave a brief presentation highlighting current activities and future plans of the Society. It was decided to constitute a

‘Veterans Forum’ amongst the group to interact & discuss on important is-sues from time to time. The proposed knowledge partner M/s CERA also gave a presentation regarding their strengths to assist the Society on such interaction.

Broad discussion on possible themes for PETROTECH-2011 was also held and members present gave their views about the same.

A brochure commemorating 10 years of glorious events was released on the occasion, besides launching of a monthly e-newsletter. A dinner was hosted by the Chairman in honour of all participants.

Ju ne 2009 55


Tribology Society of India in association with PETROTECH Society; IndianOil (R&D) and IIPM organized first ever Summer School in Tribology from 10th to 13th June 2009 at IIPM, Gurgaon. The School was inaugurated by Mr. Anand Kumar, Director (R&D), IndianOil who is present President of the Society. It was attended by 64 participants (38 from academia and 26 from industry).

Summer School in Tribology

56 Ju ne 2009


Lifetime Achievement Awardees – Petrotech-2009

Mr M K BagaiFormer CMD, HPCL

Mr S K ManglikFormer CMD, ONGC

Dr Vijay L. KelkarChairman, Finance Commission,

India & Former Secretary, MoPNG

Corporate members

The Petrotech SocietyCore 8, Scope Complex, 3rd floor, 7 Institutional Area

Lodhi Road, New Delhi - 110003Phones +91 11 2436 0872, 2436 1866

Telefax +91 11 2436 0872Email [email protected], [email protected]

Web www.petrotechsociety.org

PETROTECHSociety

Petrotech Journal June 2009

Documents

Transcript of Petrotech Journal June 2009