Final Presentation (2)

FINAL SEMINAR

“PRODUCTION OPTIMIZATION BY HYDRAULIC FRACTURING IN SHALE GAS RESERVOIR”

Department of Petroleum & Gas EngineeringFaculty of Engineering

Balochistan University of Information Technology, Engineering & Management Sciences, Quetta

28th August, 2015

GROUP SUPERVISIOREngr. Azizullah Shaikh

GROUP MEMBERSKamran Khan Kakar (19633)

Syed Siraj Ahmed (16849)Syed Israrullah (18649)

Bilal Ahmed (17757)Ahmel Khan (16201)

Muhammad Tariq (18109)

OUTLINES• Introduction• Aims and Objectives• Scope of Project• Literature Review• Methodology• Results and Analysis• Conclusion and Recommendation• References

INTRODUCTION

Well Stimulation:

Types:• Acidizing• Hydraulic fracturing

INTRODUCTION Continued…..

• Why Hydraulic Fracturing?

• Creating Permeability

• Communicating Reservoir to the wellbore

• Increase reservoir Production

TYPES:

1. Acid Fracturing Formation is treated with acid to increase/create Permeability. (HCL)

2.Propped Hydraulic FracturingPropping agents are used to “prop open” the fracture


syed siraj

hydraulic fracturing effectively increases permeability, allowing large volumes of oil and gas to be produced from unconventional reservoirs

What is Shale? Sedimentary rock formed from silt and clay particles.

Types• Carbonaceous shale (Composed of organic

matter)

• Calcareous shale (CaCO3)

• Siliceous Shale (SiO2)• Clay Shale (Chloride, Clay minerals)


What is Shale Gas Reservoir?

• Unconventional Reservoir Having Very low permeability.• Produced from Organic Rich Shale. ( TOC > 2 % )• Shale is Source Rock that is not migrated to the

permeable zone.• Composed of 90% or more CH4 .

Shale have tremendous Potential to produce Hydrocarbon.


HOW SHALE RESERVOIRS ARE FORMED?

1. Sedimentation & bacterial degradation

2. Transformation of organic matter

3. Migration

4. Petroleum with in reservoir rock


Conventional ReservoirsThose reservoirs which can produce

hydrocarbon by its own natural energy.

Examples: Carbonate rock, Sandstone, Limestone etc

Un Conventional ReservoirsThose reservoirs which required EOR techniques and hydraulic

fracturing to produce hydrocarbon.Example: Shale, Coal bed methane,

Tight Gas


How it is produced?

Shale Gas Hydraulic Fracturing

Injecting pressurized fluids

Fracture shale formation (Stimulate)

Release natural Gas


AIMS AND OBJECTIVES To increase the flow rate of oil and gas from low-permeability reservoirs To enhance/increase the flow rate of oil & gas from wells that have been damaged To join the natural fractures in formation near the wellbore To reduce the pressure drop around the wellbore for minimizing sand production To enhance gravel-packing sand placement To reduce the pressure drop around the wellbore to reduce the problems with

asphaltine and paraffin deposition To increase the area of drainage or the amount of formation in contact with the wellTo communicate the full vertical extent of a reservoir to a slanted or horizontal well

SCOPE OF PROJECT

To improve groundwater wells As a means of enhancing waste remediation, usually hydrocarbon waste

or spills To dispose waste product by injection deep into rock To measure stress/force in the Earth For electricity generation in increasing geothermal systems To enhance injection rates for geologic sequestration of CO2

LITERATURE REVIEW

• Stanolind Oil and Gas Co. in (1948)

• J.B Clark (1949)

• 100,000 hydraulic fracturing treatments (1955)

• Kansas (1947) performed while Veach reported (1989) for approximately 10,000 gallons on NAPALM

LITERATURE REVIEW Continued…History of Hydraulic Frac: Through Shale Formation In Pakistan• In 2009 Survey, Pakistan stands 19th through out the world in shale reserves (51 Trillion Cubic Feet)• EIA in 2011 established that estimates of 52 Trillion Cubic Feet of shale reserves in

Pakistan• Pakistan is left with 23 TCF of Natural gas reserves and they are expected to deplete in

2025 so then only possibility to hit Shale Reservoirs

Location of Shale Reserves in Pakistan• Under the Punjab and majority mainly upper Sindh province of Pakistan• khyber Pakhtunkhwa, under the Indus basin region, predominantly Ranikot and

Sembar• The future of the basin is an important Baluchistan basin and northern Indus basin

along with south Indus basin and the central Indus River basin

GLOBAL PRESPECTIVE OF SHALE OIL & GAS DEVELOPMENT

Shale oil and gas reserve in major countries Shale Oil and Gas Reserves in major Countries of Asia Countries Recoverable Shale

Oil Reserves, (Billion Barrels)

Recoverable Shale Gas Reserves, (Trillion cu-ft)

USA 58 862

Argentina 27 802

Australia 18 437

Venezuela 13 11

Mexico 13 681

Canada 8.8 388

Algeria n/a 707

South Africa n/a 485

UK 0.7 26

Countries

Technically Recoverable Shale Oil Reserves (Billion Barrels)

Technically Recoverable Shale Gas Reserves(Trillion cu-ft)

China 32 1275

Indonesia 7.9 574

Pakistan 9.1 51

Libya 26 290

India n/a 63

HYDRAULIC FRACTURING ADDITIVESS.no Additives type Description of purpose Examples of chemical

1. Prop pant Props open the fracture and allows fluid to flow of

more freely to the wellbore

1. Centered bauxite.

2. zirconium oxide.

3. Ceramic beads.

2. Acids Cleans up perforation HCl (3 to 28 %)

3. Braker Reduces the viscosity of fluid Per oxi desulphates

4. Corrosion Inhibitors Reduces rust formation on steel tubing Bi-shulphate for oxygen scavengers

5. Cross linkers Used to increase fluid viscosity Potassium hydroxide,Borate salt

6. Friction reducer Allow fracture fluid to be injected at optimum rates

and pressure by minimizing friction

Petroleum distillates

7. jellying agents Increases fracturing fluid viscosity Petroleum distillates

8. Iron control Prevents carbonates and sulphates from plugging

off the formation

Ammonium chloride, Ethylene glycol

9. Solvent Used to control wettability of contact surfaces Various aromatic hydrocarbon

10. Surfactants Used to reduce surface tension b/w two fluid methanol

FRACTURING FLUIDS AND CONDITIONS FOR THEIR USEBase Fluid Fluid Type Main Composition Used For

Water

Linear Cross-linked Micellar

Guar, Cross-linker+Guar,HPG, CMHPG or CMHECElectrolyte and Surfactant

Short Fractures, low temperatureLong Fractures, High temperatureModerate length fractures, moderate temperature.

Foam

Water Based Acid Based Alcohol Based

Foamer+N2 Or CO2Foamer + N2Methanol + Foamer+ N2

Low Pressure Formations Low Pressure, Carbonate formationsLow Pressure, water-sensitive formations

Oil

Linear Cross-linked Water Emulsion

Gelling AgentGelling Agent + Cross-linkerWater+ Oil + Emulsifier

Short fractures, water sensitive formationsLong fractures, water sensitive formationsModerate length fractures, good fluid loss control.

Acid

Linear Cross-linked Oil Emulsion

Guar or HPGCross-linker + Guar + HPGAcid + Oil + Emulsifier

Short fractures, Carbonate formationsLonger, wider fractures, Carbonate formationsModerate length fractures, Carbonate formations

Slick Water

Slick water is a fresh or saline water containing high molecular weight polymers that inhibit turbulence and reduce pressure loss due to turbulent fluid as they are pumped into the formation. Slick water is most effective in hard, brittle shale.

VARIOUS FLUID REQUIRED FOR HYDRAULIC FRACTURING TREATMENT

• Oil based Frac Fluids: To avoid the freezing of injected fluid in cold weather (Gasoline, Kerosene and Diesel oil)

• Water based Frac Fluids: The additive are easily soluble, it is cheaper & easily available than other fluids

• Alcohol based frac Fluids: They are used to open the plugged channels to release the gas from shale

• Acid Frac Fluids: Limestone and dolomite are dissolved by acid fracturing treatment

• Surfactants: Used to reduce surface tension b/w two fluids.(Methanol)

• Clay Stabilizers: To protect formation from swelling

• Polymers: It is used to viscosified the fracture fluid

• Viscosity breaker: It is used to reduce the viscosity

• Biocides: It is used to stop the growth of algae, fungi and bacteria

• Slick water Additives: That stop the turbulence and reduce pressure loss

• Toxic Chemicals and Radioactive Materials• Sources of water Contamination• Sources of air contamination• Sand & proppant • Oil spills• Health concern• Fracture Containment

CHALLENGES IN HYDRAULIC FRACTURING

Toxic Chemicals and Radioactive Materials

• It can create major problems

• Handle carefully during fracturing and after fracturing

• Contaminate drinking water

• Handling in the surface carefully

CHALLENGES IN HYDRAULIC FRACTURING Continued…..

SOURCES OF WATER CONTAMINATION Water Acquisition• Two to Four Million gallons of water is required to fracture a single shale.• It must be store in Storage tanks and Pits

On site chemical Mixing• Average 3 million gallons of water are required for injection 15,000 to 60,000 gallons

of chemical additives into the well• Due to the large amount of chemical additives required, there is a risk of releasing to

surface and ground water through on-site spills or leaks


SOURCES OF WATER CONTAMINATION Cont…..• Well Injection Proper casing and cementing job must be done in well

• Flow back and Produced Flow back containing the initial fracking fluids as well as naturally occurring toxic and radioactive substances return to the surface

• Waste water Treatment and Waste Disposal The flow back waste water is either reused or discharged to surface water


SOURCES OF AIR CONTAMINATION

• Venting and Flaring The produced gas must be flare OR Vent at the start • Dehydration Units Contain amine• Condensate Tanks vent vapors of these chemicals Into the atmosphere Evaporation Pits It is used to evaporate waste water and dehydration waste water


Sand & Proppant

• It is un wanted sand and Proppant after the fracturing

• It is due to the small size of sand and Proppants separate from the fracturing fluids and formation sands

• To control sand and Proppants gravel pack is used


Oil Spills

• Release of crude oil and liquid hydrocarbons into the environment

• It is specially in marine areas and also occur on land

• Oil spill is due to release of industrial waste, crude oil from tanker, drilling rigs and wells

• It can create immediate fire hazards and can also pollute the air


FRACTURE CONTAINMENT• Failure to control fracture height growth

during hydraulic fracturing

• It can decrease our production rate

• The in flow of water into well bore from fresh water zone

• In fracturing process the fracture height must be control for better fracturing

• Lower the fracture height greater the fracture length


HEALTH AND CONCERN

• A potential health impacts are chemicals used in fracturing processing and delivery of natural gas

• Chemicals could effect the skin, eyes & other respiratory system

• These chemicals should be examined by health experts

• Chemical must be handle carefully during injection


METHODOLOGYFRACTURING EQUIPMENTS:

Fracturing-fluid tanks• Hold/store Fluids

• Fluid tanks are available in several shapes and sizes

• Tanks are lined to prevent iron from hydraulic fracturing

BULK HANDLING EQUIPMENTS FOR HANDLING

• It is used to transport proppant to the blender

• Capacity is between 2000-4000 cubic feet

• On the basis of gravity the proppant feed into the blender

FRACTURING EQUIPMENTS Continued

Fluid/Proppant Proportioners• Liquid /proppant proportioners are also

called blenders

• They are used to transmit all the pre-mixed fluid, different liquids, dehydrated additives and proppant

• Inject high pressure into down hole


PUMPING UNITS

• Conventional Pumps are used to supply the essential horsepower to produce and to extend the required fracture

• Conventional pumps are used for a pressure from( 0 - 10,000 psi)

• Conventional pumps if used for long pump times (more than 2 hours)


INJECTION MANIFOLD/HEADERS• Connecting each unit to the mixer

• The high-pressure treatment line to the well head

• Top suction manifolds are used to close the mixer to the pump units

• Attach the pump to properly treat line


WELLHEAD ISOLATION• High pressure, corrosive fluids and

Proppant damage wellhead

• Specialized instrument insulation is used to protect Christmas tree wellhead from damage

• A rubber cup assembly of mandrel seals to the tubing walls and protect the tree from fluid and pressure

• Wellhead isolation tools are available to manage pressure up to 20,000 psi


HORIZONTAL DRILLING & HYDRAULIC FRACTURING• Used to maximize well contact with

target hydrocarbon reservoirs

• Used to increase hydraulic connectivity within the formation

• To produce economic quantities of oil and gas from low-permeability formations

CASE STUDIESCase Study No: 1Hydraulic fracturing in the Dutch Posedonia Shale

• Vertical well and horizontal well drilling

• Posedonia shale has porosity up to 10 % and Permeability 10 nD

• Comparative study between Dutch Posedonia shale and three shale gases in USA

RESULTS AND ANALYSIS

Effect of fracture spacing in complete partially propped fracture • Increasing the number of stages will

decrease the distance between these clusters

• Many American shales are brittle and hard, but if a shale is very soft there will be no blocks to rotate and thus no self-propping

CASE STUDIES Continued….Case Study No: 1 Continued…

Results from Case Study No:1• Dutch Posedonia having high TOC and porosity is good candidate for shale gas

production

• Result suggested that it is having high young modulus, low poison ratio and low stress anisotropy

• Posedonia shale is very soft and require high viscous fracturing fluid

• Large Stimulated reservoir volume by increase in fracture density to enhance fracture conductivity

• More testing on samples are performed to reduce uncertainty

CASE STUDIES Continued….

Case Study No: 2Hydraulic Fracturing design and the use of qualitative data (Eagle Ford Gas-Shale)• Stimulation to the flow of hydrocarbon in

all shale formation is not in the same manner.

• Major qualitative components of fracture design are:

1. Reservoir Characterization 2. Design Consideration

Pretreatment Flow DataChoke size inches WHP

psiBHP psi Q(mmscf

d)PI scfd/psi

0.5 inches 1513 2075 09 7435

0.625 inches 1145 1761 11 6910

0.75 inches 868 1545 12 6373

Post-treatment Flow Data

Chock size inches WHP psi

BHP psi Q(mmscfd)

PI scfd/psi Increase PI

0.5 inches 2092 2764 13 1917 158%

0.625 inches 1739 2534 17 1657 140%

0.75 inches 1419 2375 20 15052 136%


• Reservoir properties of Eagle ford shale from core data

• Larger mesh size proppant were used to maintain conductivity of fracture channel

Parameters Unit Range

Total organic Carbon

% 2 – 9

Porosity % 8 -18

Water saturation % 7 – 31

Permeability Nano dacrcies 20 – 1, 200

Static young’s modulus

Pounds / square inch

1.00 E+ 06 – 2.50 E 06

Poisson ratio 0.25 – 0.27


Case Study No: 2 Continued…

Hydraulic Fracturing design and the use of qualitative data (Eagle Ford Gas-Shale)

• At the beginning of fracture treatment, both fluid injection rate (Qinj) and specific design fluid viscosity µ of the frac fluid are essential to create required system of fracture

• Ductile shale, such that most of eagle fork requires highly viscous fracturing fluid• Shallow reservoir depths allow placement of high concentration (4lbs/gallon) of large

mesh proppant (20/40 mesh) with slick water; but deeper depths require more viscous fluids

• Large proppant size having higher conductivity is used for liquid gas production.• Proppant embedment, crushed proppants, formation fines and proppant digenesis may

have major impact on conductivity with time• Surface modifying agents such as surfactants, cross linker, inhibiters can help to

minimize the effect of slow proppant-pack conductivity with time

Results from Case Study No:2


Case Study No: 3Optimizing Hydraulic Fracturing Performance in Northeastern United States Fractured Shale Formations• Comparison studies of micro emulsion system

with conventional surfactants (CS) when injected into shale

• Identifying effectiveness of micro emulsion vs conventional surfactants (CS) in regaining permeability

• Presenting and production data where multiphase fluid treatments have improved fluid recoveries


Case Study No: 3 Continued…Optimizing Hydraulic Fracturing Performance in Northeastern United States Fractured Shale Formations

• Reservoir and production information from 24 wells

• All 24 wells were treated 23,000 bbl of water 110,000 lb of 40/70 sand 250,000 lb of 20/40 sand tail in at 65 BPM

CS wells

Top Pert

Bottom Pert

h (ft) k (mD)

kh (mD-ft)

ISIP-15m

Calc k Calc kh

1 6896 7196 300 0.002 0.6 104 0.0021 0.632 6823 7130 307 0.002 0.614 100 0.0017 0.793 6776 7104 328 0.002 0.656 80 0.0026 1.074 6944 7296 352 0.002 0.704 253 0.0014 0.735 6870 7220 350 0.002 0.7 111 0.0006 0.306 6743 7038 295 0.002 0.56 297 0.0010 0.307 7285 7642 357 0.002 0.714 106 0.0031 1.108 6822 7116 294 0.002 0.588 33 0.0059 1.719 6862 7170 308 0.002 0.616 70 0.0059 1.7110 6854 7175 321 0.002 0.642 200 0.0012 0.36

11 7144 7500 356 0.002 0.712 73 0.0034 1.1112 6940 7244 333 0.002 0.608 290 0.0019 0.54MA Wells

1 7400 7756 331 0.002 0.712 42 0.0046 1.642 6823 7156 314 0.002 0.666 123 0.0070 1.743 6812 7134 319 0.002 0.644 40 0.0041 1.504 6879 7210 289 0.002 0.662 140 0.0059 1.895 6788 7102 327 0.002 0.628 140 0.0009 0.296 6845 7164 333 0.002 0.638 100 0.0060 1.797 6811 7100 336 0.002 0.578 285 0.0041 1.188 7073 7400 319 0.002 0.654 250 0.0021 0.549 6781 7114 312 0.002 0.666 220 0.0030 1.0010 6960 7296 322 0.002 0.672 220 0.0029 1.0011 6981 7300 295 0.002 0.638 41 0.0052 1.6912 7328 7640 296 0.002 0.624 107 0.0025 0.78


• Study compiling data on Devonian shale formation and Rhine Street shale formation showing there on attributes and characteristics.

• Core data displace that water saturation is decrease, Relative permeability to gas is increased and capillary pressure is cut in half when micro emulsion is introduced.

• Low permeability core clean up test show that pressure to start cleanup is reduced by 50% and regained permeability to gas is doubled.

• The addition of micro emulsion to fracturing treatment as resulted in 50 % increase in recoveries of gas production.

Results from Case Study No:3


CONCLUSION AND RECOMMENDATIONSConclusion:• To measure and approach to reduce land disturbance and land-take

• To measure and to reduce noise during drilling, fracturing and completion

• To measure to address water resource depletion

• To measure to reduce the negative effects caused by increased traffic movements

• To improve well integrity and to reduce the risk of ground and surface water contamination

• To reduce the pressure on biodiversity

CONCLUSION AND RECOMMENDATIONSRecommendations:• To use of micro-seismic monitoring in relation to hydraulic fracturing

• To determine chemical interactions between fracturing fluids and different shale rocks, and displacement of formation fluids

• To induce seismicity triggered by hydraulic fracturing

• to improve well integrity through development of better casing and cementing methods and practices

• To research into the risks and causes of methane migration to groundwater from shale gas extraction

• To develop a system of voluntary ecological initiatives within sensitive habitats

• Proper guidance, effective equipment and installations are operated that will assist and prevent different hazards from the human as well as environment and atmosphere

REFERENCESErle C .Donaldson Waqai Alam and Nasreen Begum Tetrahedron, Inc; hydraulic

fracturing explained Economides J. Michael , Hill A. Daniel, Petroleum Production Systems, 1993 Economides, M. J., Nolte, K. G., 2000: “Reservoir Stimulation (3rd ed.)”. John Wiley &

sons, Ltd., Chichester, England, UKM . JANSZEN, delft university of technology ; T bakker well engineering partners; P.L.J

zitha, Delft University of technology, binga EnergyProduction Technology II Module, Heriot Watt University, UK, 2007, by Dr. David

Davies. Shale oil and gas life line for Pakistan by Engr Arshad H.AbbasiTalbot D.M, Hemke K.A. and Leshchshyn T.H: “Stimulation Fracture Height Control

above Water or Depleted Zones,” SPE 60318, presented in Rocky Mountain Regional/Low Permeability Reservoirs Symposium, Denver, Colorado, 12 – 15 March 2000.

REFERENCESWine J.D, DeBonis M.P. and Thomas R.L: “The Effect of Guar and HPG Cross linked

Fracturing Fluids on Well Performance: A Case Study,” SPE 18969, presented in Rocky Mountain Regional/Low Permeability Reservoirs Symposium, Denver, Colorado, 6 – 8 March 1989.

Vidic, R.D., Brantley, S.L., Vandenbosshe, J.M., Yoxtheimer, D., and Abad, J.D., 2013. Impact of Shale Gas Development on Regional Water Quality. Science Vol. 340, 17 May 2103.

Westgaard, G., 2002. Securing a License to Operate: The Role of Corporate Social Responsibility. 17th World Petroleum Congress, September 1-5, 2002, Rio de Janeiro, Brazil. Conference Paper 32406.

Zimmerman, M, Patterson, K., Hedgcoxe, H.R, and Houghton, J., 2013. Groundwater Monitoring in the Eagle Ford: Evaluating Baseline Conditions in a Risk Management Context. SPE Americas E&P Health, Safety, Security and Environmental Conference, Galveston, Texas, USA, 18-20 March 2013. SPE 163763.

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