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4LI'IilIIta\rtr7 r\tI7UNTVERSITITEKNOLOGIm:rmffiCOURSEDATETIME

PAB2O94 WELL COMPLETIONSNDPRODUGTION

15 NOVEMBER008 SATURDAY)9.00AM- 12.00NOON 3 hours)

INSTRUCTIONSO CANDIDATES1.2.3.4.

5.

AnswerFIVE 5)out of $lX (6)questionsrom heQuestionBooklet.BeginEACHansweron a newpage n the AnswerBooklet.Indicate learlyanswershatarecancelled,f any.Whereapplicable, how clearlysteps aken n anivingat the solutions ndindicateALL assumptions.Do notopen hisQuestionBooklet ntil nstructed.

Note : ThereareNINE 9)pages nthisQuestionBookletncludinghe coverpageandappendix.

Universiti Teknologi PETRONAS

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1.PAB2094

Explain he following erms used in the study of hydrocarbon ell'sproduction erformance.

Productivityndex

ii. Pressure rawdown

iii. Absoluteopen-flow otential[2 marksJ

b. A reservoirhas been producing nder stabilized low conditions t1200 bbl/daywith a flowingbottomhole pressureof 1600 psi. Theaverage reservoirpressure s 3100 psi. Calculate he productivityindex.

[4 marks]c. Determine he specific productivity ndex for a well producingat

1500 bbl/daywith a flowing bottom hole pressureof 2100 psi, atreservoir hicknessof 4O ft and an average reservoirpressure of4000psi.

[5 marks]d. lf a secondwell in the same oil field as in part (c) penetrateshe

reservoirat a locationwhere he reservoirhickness s 50 ft, calculatethe flowing bottom hole pressureat the same rate as the well inpart (c).

2

[2 marks]

[2 marksJ

[5 marks]

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2.PAB2094

An oilwellhas beendril led y an Oil andGasCompany.When t was oundthat herewere hreeproductiveones n thiswell, t is requiredo accomplishbottom-holeompletionso producewell luid rom hiswell.Well Completionswould include packers and Sub Surface Safety Valves (SSSV). Theinformationbout hese hreeproductiveones s listedn the TABLEQ2.

TABLE Q2Productive

Zone DepthBottom-hole

PressureType

of FluidSpecific

GravityofFluid

Zone 1 7000 t. 2000psi Oil+Gas 0.76Zone2 7050 t. 2300psi Oil+Gas 0.76Zone3 7150 t. 2700psi Oil+Gas 0.8

What type of well completions an you install n this well? Drawsketches f the completions ndexplainbriefly f theCompanyplans oproduce:

FromZone 1 only. [3marksJii. From Zone1 and Zone2 simultaneously.

[5marks]i i i . From Zonel, ZoneZ,andZone3 simultaneously.

[7marks]to be considered hen choosing

[5 marks]

a.

b. List FIVE (5) factors that needdifferentypes of completions.

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3kP *.^9 PAB2094

when sand is produced ogetherwith welr fruid, erosionand corrosionproblems ouldoccurat equipment sed nthewell luidproductionystem.a. Deflne WO 2)sandcontroltechniques.

[4marks]b. Draw sketch fsrotted ipeandexptaintsprincipres.

[5marks]of a wirewrapped creen nd ts functions

[5marksJDiscuss the process and surface operation procedure for gravelpacking.

[6marks]

c.

d.

Describehe constructionandusage.

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a..

b.

PAB2094Compare the matrix acidisingand fracturing treatmentswhenconsideringarrying ut a stimulationreatment n a well.

[5 marks]

Explain WO 2) sources f formation amage ncountereduring;

drilling ndcompletion perations[3 marks]

ii . productionPerations[3 marks]

c. Yourservice ompany asdesignedhe ollowingracturingreatmentsas istednTABLEQ4.

TABLEQ4Wellboreadius, . 0.328 tReservoir eight, r 100 ft (boundedby competent

shales)Reservoir ermeability, 0.1mDProppant vailable 300000 bDesign racture onductivitY,kf-w

Treatment- 1500mD.ft at 4',bffi2

proppantoadingTreatmentB

- 850mD.ft at 2lbtt(proppantoading

UsingCinco-Ley nd Samaniego lot inyourmanagement hetherreatment orwell productivities.(Hint Compareboth racture kin,Sj

FIGUREQ4, adviseB willgive he highest

5.

[6 marks]

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FIGURE 4

ii. Justify ouranswern part (cXi)?

PAB2094

[3 marks]

\ t i

\

tL

I1-

3J

;(t

0.1 10 100F6e= kf-wk.(Lf)

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6.PAB2094

A well is partially ompletedwith only 4.92 ft perforated ut of a total of18.04 t net pay hickness. he results rom he buildup nalysisndicates sapparent kin, S'of 5.0,suggesting ellbore amage.Reservoir ata aretabulatedn TABLEQ6.

TABLEQ6Pay hickness 18.04tPerforatednterval 4.92ftFractionalenetration 0.27Horizontalo verticalpermeabilityatio,KJKa 100Wellboreadius 0.2493ftlnitial eservoir ressure 141.1 siBottomholelowing ressure 70.3psiPressure ropdue o skin 33.1 siTestgasrate partial ompletion) 10x 10"m"/d

Calculatehe skin actordue o partial enetration,o or hiswell if ithas he ollowingK"/Knratio:

1,10,50and100.[8 marks]

ii. Explain heeffectof K"/Kn atioon theSr.[2marks]

Determine he improvement n productivity f entire payzone isperforated.

[10marks]

- ENDOF PAPER.

a.

b.

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lnflowPerformance elationshipor Steady-Statelowconditionl4l.ZaBul \P,-P,4*#[t";. ' ,J

lnflowPerformance elationshipor Pseudo-Steady-Statelowcondition= - - l4t .2qBp(rnL-l*r)P- P,, '1 '= kh:[ , , ' ' ' 4 ' - )

Fracture onductivi k"* wty,F"r='.t, Zr= Fracture alf ength

Fracture ength= proppantIoading x fracture _ height

Ffowefficiency P'- \t - M'a'P, P*t

I

Zr= Fracture alf ength