The Formulation of Water Based Drilling Fluid From Local Materials

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Caspian Journal of Applied Sciences Research, 2(1), pp. 18-22, 2013

Available online at http://www.cjasr.com

ISSN: 2251-9114, 2012 CJASR

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Full Length Research Paper

The Formulation Of Water Based Drilling Fluid From Local Materials

O.N. EKEIGWE*1

, C.K. ANYIAM2, M.D. AYO

3and L.O. EKEBAFE

3

1Department of Pure and Industrial Chemistry, AnambraState University, Uli, Nigeria

2Department of Polymer and Textile Engineering, Federal University of Technology, Owerri, Nigeria

3Polymer Technology Department, Auchi Polytechnic, PMB 13, Auchi, Nigeria

E-mail: [email protected] Telephone: +234-806-957-8855

Received 01 October 2012; Accepted 01 December 2012

The fluid loss property of mud formulated with variable quantities of starch and cellulose extracted from

cassava and their rheological properties have been studied. The outcome was compared with those of the

standard mud formulated from Polyanionic Cellulose (PAC) and Industrial starc. The results show that

increasing the concentration of starch in the mud system does not give a significant change in fluid loss property.

Which suggest that Cellulose is a better fluid loss control agent than Starch. Hence these polymers have

potentials as polymeric additives for drilling mud. Also, the water loss analysis showed that the local drilling

fluid has a lower fluid loss of between 3.20-7.70 mls and a Plastic viscosity (PV) value of 10 centipoids (Cp) as

against 14 Cp of the standard mud. Confirming that the local (Polymer) mud has the ability to maintain optimal

pressure and torque in the borehole, hence preventing the problem of stuck pipe during drilling operations.

Again, the Polymer mud has a yield point of 30lbs/1000ft2 as against 42lbs/1000ft

2 of the standard mud.

Confirming that the polymer mud conforms to the standard range of (30-40lbs/1000ft2) as the required range of

Yield Point (YP) that will ensure the removal of cuttings from a large diameter hole.

Key words: Hura Crepitans; Rheological properties, polyanionic cellulose (PAC), yield point, plastic viscosity,

Standard mud

1. INTRODUCTION

Drilling fluid is a mixture consisting of solids,

liquids and gases distributed throughout a liquid orgaseous phase, which is circulated through the well

bore during rotary drilling process, Acevedo(2007).

The search for greener products for well boredrilling that will achieve a good level of

performance particularly with local materials isbeing intensified. Although, substantial strideshave been made in the development ofenvironmentally friendly, sound performancechemistry for corrosion inhibition, demulsifiersetc, much has not been done in the development ofsuch mud systems with local materials. Drillingoperations rely heavily on the use of water basedmuds. Acevedo, (2007). and Gray (1988). Theseare mixtures of solids, liquids and chemicals.Water is the continuous phase. Active solids likebentonite are added to the water. Bentonite acts

mainly as the dispersed phase providing the maingel structure. Chemical additives are added invarious proportions to control the fluid properties.

These chemicals additives are commonly used forthe control of pH, viscosity, weight, fluid lossRogers, (1963). The major success of every

drilling operation depends solely on theperformance of its drilling fluids.

In the cause of the continuous search forefficient, biodegradable and environmentallyfriendly polymers for use in the formulation ofdrilling muds, the objective of this work is to study

the applicability in the formulation of a drillingmud of starch extracted from cassava and celluloseextracted from cassava stem.

These additives would be used to replaceconventional polymers as fluid loss agents.

The search for petroleum reserves has becomesignificantly more expensive with the move intodeep-water, and more hostile environment, whereit becomes very necessary for drilling operations toexcel in many performance categories,Bello M.A(2001):. Measurement of performanceencompasses all key parameters of drilling

operation and their associated cost. A fluid isevaluated by its influence on overall wellcost,Darley and Gray(1988), Abdon(1989).


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Drilling fluids have various functions of assuring asafe and speedy drilling operation at minimumoverall cost.

2. MATERIALS AND METHODS

2.1 CASSAVA STARCH EXTRACTION

The cassava tuber was harvested from a farmlandin Ehime Mbano, Imo State, Nigeria, peeled,

grated and water added, while sieving with a whitecloth to separate the chaff from the liquid (syrup),

after which it was dried under the sun to preventfermentation. All the reagents used in this researchwork were supplied by Best Land and Sea Services(BLS) Port-Harcourt, Nigeria and are of analytical

grade. Acevedo J.C, (2007)

2.2 CASSAVA CELLULOSE EXTRACTION

The whitish substance found in the stem of cassavawas extracted and treated with 17% sodiumhydroxide solution and allowed to stay for fewhours after which it was reacted with 2% solutionof chloroacetic acid, stirred and allowed to standfor few hours and the resultant material washedand blended into a very fine powdered form.Acevedo J.C, (2007)

2.3 Bentonite Preparation.

10grams of bentonite was dissolved in 350mls ofwater and properly mixed using electric mixer for5 mins. The resultant solution was left overnightfor proper yielding.

2.4 Mud Formulation Procedure

350mls of bentonite solution was measured outinto the electric mixer and the correct measurement

of each material additive added at 5mins intervalaccording to order of additive in Table 1. Afterabout 30mins, the resultant mud was brought downfor weighing with mud balance.

350mls of the bentonite solution was agitated in

the mixer and each material additive was added atfive minutes interval according to order ofadditives and the resultant mud was agitated for aperiod of one hour, Anchor(1985)

2.5 Preparation of Polymer (study) Mud

The preparation of the polymer mud was same asabove but for the replacement of PAC with cassavacellulose (1.50g) and Industrial starch with cassavastarch (4.00g). Subsequent formulations were

carried out by varying the concentration of thecassava starch and cassava cellulose

3. RESULTS AND DISCUSSION

3.1 SHEAR STRESS / SHEAR RATE

From Tables 2 and 3, it could be deduced that thereis a remarkable increase between shear rates andshear stress hence the shear rates of the two mudsystems increased with increase shear stress,

exhibiting behavior close to the Bingham plasticmodel at a marked difference from the Newtonianfluid model as the line does not pass through theorigin when a graph of sheer- stress is plottedagainst shear rate in Fig (1)

Shear stress is the resistance which opposesshearing and until the applied force exceeds theyield stress, flow will not be initiated, Beihoffer etal (1990).

The yield stress that must be exceeded for flowto be initiated is the "yield point"

Table 1:Standard Mud Preparation Composition


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Table 2:Results of Standard mud (PAC+ Industrial Starch)

Table 3:Results of Polymer Starch Mud (Cassava Cellulose + Cassava Starch)

From Tables 2 and 3, a plot of viscosity againstshear rates shows that increase in shear rate also

decreases the viscosities thus suggesting that thetwo mud systems have good hole cleaningproperties hence they are good drilling fluids,Beihoffer et al, (1992), Bethlen (1990).

The higher viscosity values for the standardmud suggest that there is a higher degree ofsubstitution by carboxyl groups causing thepolymer to have a higher degree of dispersion oryield in the mud causing the polymer chains touncoil, this subsequently causes the long andstraightened polymer chains to bridge togetherforming a structure which raises viscosity, Bland(1991), OBrien and Chenvert (1973), and Baroid(1999).

From Tables 4, standard mud has higher fluidloss compared to polymer mud.

The two systems have same fluid loss value of5.80cm3 at 10min in standard mud and at 25min inpolymer mud which goes to show that polymermuds are good for filtration control at the well sitesince this is the only practical test that gives aninsight into the ability of a mud system to controlfiltration loss into formation, lwu I.C, (2003):Onwuta V., (1989), Osuji C.E, (2008):. There seemto be an initial high rate of fluid loss in polymermuds, which later decreased with time. Thedecrease is suspected to be as a result of theformation of filter cake on the filter paper, whichminimizes the fluid loss as it is deposited, OBrienand Chenvert (1973), and Baroid (1999).

Table 4;Fluid Loss Vs Time for Standard Mud.(SM) and Polymer Mud (PM).


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Fig 1. Plot of Shear Stress Vs. Shear rate

Fig 2. Plot of viscosity against shear ract

4. CONCLUSION

Drilling fluids (muds) have been formulated fromlocal materials (cassava starch and cellulose). Theresults show that increasing the concentration of

starch in the mud system does not give asignificant change in fluid loss property. Which

suggest that Cellulose is a better fluid loss controlagent than Starch. Hence these polymers havepotentials as polymeric additives for drilling mud.Increase in the concentration of cassava celluloseto 4.5ppg gave a fluid loss value of 5mls while

cassava starch is suitable for mud with highsalinity as they are not liable to bacterialdegradation but not for mud exposed to high

temperature of about 94C due to theirsusceptibility to thermal degradation. Polymermuds produced are cheap and dissolve readilywithout the tendency to form fish eyes. Thisinherent property of these polymer muds, coupled

with its cheapness, would account for a reducedoverall well cost. Increase in the concentration of

the cassava cellulose will only introduce pressure,which is a negligible factor in the rheoiogy ofwater base muds. The comparative study of therheological test results of the two mud systemsshows outstanding properties exhibited by the

polymer mud as regards plastic viscosity (PV), gelstrength and yield Point (YP).


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REFERENCES

Flocculated Polymer Mud for HTHP Drilling, SPE17924, Presented at the SPE Middle-East OilTechnical Conference & Exhibition, Bahrain,

March 11-14.Acevedo, J.C, (2007); M.Sc Thesis on Shale

Membrane Efficiency Experimental StudyUsing Water Base Muds University of Texasat Austin.

Anchor Drilling Fluids (1985); Engineering Manual,Edition No1.

Beihoffer, T.W. et al, (1990); The Development ofan Inhibitive Cationic Drilling Fluid for Slim-Hole Coring Applications, SPE Paper 19953,

presented at the 1990 SPE/IADC DrillingConference, Houston, Feb.27-Mar.2.

Beihoffer, T.W., et al, (1992); Cationic PolymerDrilling Fluid can sometimes replace Oil-baseMud, Oil and Gas Journal. Vol. 90.

Bello M.A (2001): Polymers-The Chemistry andTechnology of Modern Materials; ConceptPublications Lagos, Nigeria, pp116-118

Bethlen, G.A., (1990); Application of the Therma-Drill System in Eastern Venezuela, 21stPetroleum conference and Exhibition Siofok,Hungary, September 26-30.

Bland, R. (1991); Development of New Water-BaseMud formulations, Royal Society ofChemistry, Vol.97, pp83-98.

Darley, C.H. & Gray, R.G., (1988); Compositionand Properties of Drilling and Completion

Fluids. (Fifth Edition), Gulf PublishingCompany, April 5, page 401-415

lwu I.C, (2003): M.Sc Thesis on "Physico-ChemicalCharacterization of Some Selected Drilling

Fluid's" University of Port-Harcourt, RiversState.pp. 32-40

OBrien, D.E. & Chenevert, M.E., (1973);Stabilizing Sensitive Shales with inhibitedPotassium Base Drilling Fluids, Journal ofTechnology, pp 1089-1100.

Onwuta V., (1989), An integrate Approach forSolution and Treatment When DrillingThrough Troublesome Shales with WaterBased Mud. Paper SPENC 8901 Presented atSPE Nigeria Council 13th AnnualConference Lagos pp 15-30

Osuji C.E, (2008): M.Sc. Thesis on "Effect ofPorosity and Permeability On the MembraneEfficiency of Shales" University of Texas atAustin pp.54-64

The Baroid Fluids Handbook, (1999); BaroidDrilling Fluids Inc, Houston, Texas.pp.198-

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The Formulation of Water Based Drilling Fluid From Local Materials

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