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'A)NIVERSITI

COURSE

DATE

TIME

UNIVERSITI

TEKNOLOGI

PETRONAS

A1Aý

ý

YZ'IIiL*I

PAB2094 WELL COMPLETION AND PRODUCTION

11thSEPTEMBER 2011 (SUNDAY)

2.30 PM - 5.30 PM (3 HOURS)

INSTRUCTIONS TO CANDIDATES

I. Answer ALL questions from the Questions Booklet.

2. Begin EACH answer on a new page in the Answer Booklet.

3. indicate clearly answers that are cancelled, if any.

4. Where applicable, show clearly steps taken in arriving at the solutions and

indicate ALL assumptions.

5. Do not open this Question Booklet until instructed.

Note I. There are TWENTY ONE (21) pages in this Question Booklet

including the cover page and appendices.

ii. Please attach appendices on page TWELVE (12) till

NINETEEN (19) with the Answer Booklet during submission.

iii. Graph paper is provided.

Universiti Teknoi ogi PETRoNAS

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PAB 2094

I. a. The following data pertaining to Well Kerisik in a reservoir offshore Sabah.

TABLE Qia

Depth of tubing 5000 ft

Diameter of tubing 2 inch

Gas Liquid Ratio 500 scflbbl

How condition 100% oil

The results of two well tests are as follows:

Test I

Flow rate

Flowing wellhead pressure

600 bpd

360 psi

Test 2

Flow rate

Flowing wellhead pressure

1000 bpd

160psi

Determine the static pressure and productivity index from the two flow tests.

[4 marks]

2

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PAB 2094

b. A completion design is required for Well Siakap. Test results gave the following

data in TABLE Q1 b. Determine the suitable tubing size to flow the well at 400 bopd

(all oil).

TABLE Qib

Depth of tubing DO t

Wellhead pressure

Gas Liquid Ratio

Flow condition

80 psi

200 scf/bbl

100% oil

µ ...Flaw rate ý.. Wýý.. r_. 400 bopd

Productivity index 1.3 (linear)

Bubble point pressure_ 1200 psi

[4 marks]

C. Well Tioman in a reservoir offshore Terengganu have the following data in TABLE

QI o. Determine the gas liquid ratio required for the well to flow.

TABLE Qic


Wellhead pressure

Tubing diameter

80 psi

2.5 inch

Ffow condition 50% oil

Flow rate 640 bopd

Productivity index

Average reservoir pressure

4.0 (linear)

2500 psi

[4 marks]

3

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d. Well Tenggiri have the following completion and reservoir data in TABLE Q1 d.

TABLE Q1d


Diameter of tubing

ý.

2.5 inch

Gas Liquid Ratio 200 scflbbl

Productivity Index 2.1 b/d/psi (linear)

Average reservoir pressure 2500 psi

I. Construct wellhead versus flow rate curve at 600,1500 bpd in the

graph paper provided.

[6 marks]

ii. Determine the flow rate for a wellhead pressure of 150 psi.

[2 marks]

4

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PAB 2094

2 An oil well has been drilled by Gelama Gil and Gas; and they found three

productive zones in this well. It is required to accomplish bottom-hole completions

toproduce well

fluid fromthis well.

Well Completionsshould include appropriate

completion string components. The information on these three productive zones is

listed in the following TABLE Q2.

TABLE Q2

Productive Depth Bottom-I

Type Specific Corrosive

Zone hole of Fluid and Gravity ofgas

Pressure constituents Fluid

Zone 1 10000 ft 3550 psi Oil 0.77 None

Zone 2 10050 ft 3600 psi Oil, with 0.78 H2S

sand

particles

Zone 3 10150 ft 3700 psi Oil 0.77 None

a. Draw one completion diagram for each of the following cases. Indicate with

labels where appropriate and give justifications for your design.

I To produce oil from zone 1 and zone 3 whilst zone shut-in.

ii. To produce oil from zone 2 whilst zone I and zone 3 shut-in.

5

[4 marks]

[4 marks]

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PAB 2094

iii. To produce oil from zone 1 and zone 2 whilst zone 3 shut-in.

[4 marks]

b. Compare TWO (2) disadvantages each for commingled and segregated flow.

[4 marks]

C. Compare TWO (2) requirements for single zone and multiple zone completions.

[4 marks]

6

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3. The Electrical Submersible Pump (ESP) system proved to be an efficient means

of producing liquid from oil and water wells.

TABLE Q3

Pump setting depth = 4,500 ft WHP =1 00 psi Sp. Gr. Qil = 0.85

Perforations @ 5,000 ft CHP =10 psi Sp. Gr.Water =1.0

Tubing size 2 318"new Liquid Rate = 1,700 STBId Sp.Gr.Gas = 0.64

Casing ID 6.366 Static Liquid Level 1,820 ft Pi =2 bpd/psi

Bottomhole Temp = 200F Water Cut = 80% Frequency 60Hz

a. TABLE Q3 shows the setting parameters of an ESP installation running at

60 Hz in a well with negligible gas production. Calculate:

i. Liquid specific gravity from water cut, SG), SBHP, FBHP

and pump intake pressure.

[4marks]

ii. Dynamic liquid level (use grad9 = 0).

[2 marks]

iii. Solution GOR, R,s(scf/stb).

[2 marks]

iv. Oii volume factor at PIP.

[2 marks]

V. Liquid rate at pump intake.

[2 marks]

7

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b. Analyze the effect of water cut towards the FBHP and the liquid rate.

[4 marks]

C. Describe TWO (2) well conditions situation that may cause failure to ESP

equipments.[4 marks]

8

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4. A core plug has been taken from Well Kencana A3 at a depth of 3294 ft and sent

for core analysis. The Laser Particle Size Analysis (LPSA) data obtained is

plotted in FIGURE Q4.

F'GURE Q4

Laser Partsizsr Distribution

I00

80

60

40

20

I 0.1

Partieie Diameter (mm)

0.01

0

0.001

a. From FIGURE Q4 compute:

i" d,(),d90,Uniformity Coefficient(UC) and Sorting Criteria (SC).

[4 marks]

ii. Based on the calculation in Part a(i), what is the appropriate sand

exclusion method to be used?

[1 marks]

iii. Based on your answer in Part a(ii), specify the screen gauge and

gravel mesh size using TABLE Q4 in APPENDIX X.

[3 marks]

9

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b. Discuss the THREE (3) causes of sand production.

[6 marks]

C. Compare chemical and mechanical sand exclusion techniques.

[6 marks]

10

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5. a. Perforation provides communication between reservoir and wellbore.

Provide a shaped charged diagram with appropriate labels of its

components.

[3 marks]

ii. Explain underbalance and overbalance perforation.

[5 marks]

b. Compare the differences between matrix acidizing and hydraulic

fracturing.

[4 marks]

C. Scales are known to be vulnerable to the production in oil and gas

industry.

i. List out TWO (2) types of organic scales and the occurrence of

these scales.

[4 marks]

ii. Explain the thermal method of wax deposits removal.

-END OF PAPER-

11

[4 marks]

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APPENDIX H

Exam 1D:

Table No:

... - ._ ,--. »-, F ý...ý,

_ -,

-ý-! --ý-i----

.W_. ý.ý.. ý_:..

_M«. i

. [1

" . ^

ýQ . r..{,

-

:üý

y.. ý. ý... R

_f; ý.ý...

13

Fig. C.89

VERTICAI. FLOWING

PRESSURE GRADIENTS

(ALL0I1)TubingSize 2 in. I,D,

Producing ate 600 BbIs.Dayail API Gravity 35° API

GasSpecificGravity 0.65

Averagelowing emp. 140°F

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Exam !D:

Table No.

, .... ..:.. ..............

ý. _ý .,...

... ý .......i . . .

.ý.I.. .

.,_. I....

.ý....

.

Fig. C. 91

VERTICAL FLOWING

PRESSURE GRADiENTS

(Aft 0ft)TubingSize

ProducingRateOil APIGravity

GasSpecificGravityAveragelowing emp.

PA8 2094

APPENDIX III

. ;. .aý

14

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APPENDIX IV

Exam iD:

Table No:

ý-_-4 t -... -.

_. -, ý._ý., - .

}- .H_t.

ý.,., ý

i_... _

.1_A

.-

ý

r_____ .W...li.,.;ý. ,

.__. ý_.-f----'

..;_.; :}, ",

Fig. C. 101

VERTICAL FLOWING

PRESSURE GRADIENTS

(ALLOIL)TubingSire 2.5 In. 1.0.

ProducingRate 440 Bbis.4ay

Oil APIGravity 35° API


Average lowingTemp. 124°F

15

_, +

r .;: ..

l

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APPENDIX V

Exam ID:

Table No:

Fk. C.103w

VERTICAL FLOWING

PRESSURE GRADIENTS

(ALL OIL)

TubingSize 2.5 in. I.D,

Producingate 600 BbIs,Day

Oil APIGravity 35' API


Rveragelawingemp, 140°F

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PAB 2094

APPENDIX VI

Exam ! D:

Table No.

Fig. C. 105

VERT! CAL FLOWING

PRESSURE GRADIENTS

(ALLall.TubingSize 15 in, LD.

Producing ate 1000 BbIs.Day

Oil AP1Gravity 35° API


1verage lowing Temp. 140°F

f/ fl

17

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PAB 2094

APPENDIX VII

Exam ID:

Table No:

ý.. ..,

F. _ý_ý..... t......... ý

ý..F-. n

ýý.. ý

ý.4 +..

_!.

_wý . -"--M»M.

,.... Fi.. l

;.,

.;.,.._».. .

-. -. ..;..

- ýý...ýý

..

i.Lý..

ýý

. . ý . 1.

-.fý

11

.f

:_.

a...,

ý.-1

ý.ý.. . -W ..

ý.,.;..,

i4

ýý. 1,

ýY

ý.,

.;.

Fig. C. 1Ufi

VERTICAL FLOWING

PRESSURE GRADIENTS

(ALLOIL)TubingSize 2.5 in. Ud.

ProducingRate I600 Bbls.Day

Oil API Gravity 350 APIGasSpecificGravity 0.66

Average lawingTemp. 140°F

18

.ý

1..

y. ..

ý._

1ý

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APPENDIX VIII

Exam }D:

Table No:

12 16 20 24

VERTICAL FLOWING

PRESSURE GRADIENTS

(50%011-50% WATER)

TubingSize 2.5 in. t,D.

Producing afe 600 BbIs.Day

011APIGravity 350 ýPl

WaterSpecificGravity L074


Average lowingTemp. 140°F

28

ý. rý

ý n " ý .

w_.w,.

ý.1.

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APPENDIX IX

ýýýLset grad0 + CHP - PIP

grad0 ---grad9

PIPRS YA (18(1OY))

1.205

Where y=0.00091 T-0.01 25°API

T= suction temperature, °F, and

ýýgas specific gravity

API = ail API gravity

Bý = 0.0972 + 1.4710ý4F1,175

Where F=R (Yg/Yo)05 1.25 T

Yg, 0= oil and gas specific gravities

Rs solution gas-oil ratio, scflbbl

T= suction temperature, °F

R'1 qo8o + qw. $w

Where q0= oil volumetric rate, STBId

qW= water volumetric rate, BTBIdB0= oil volume factor at pump suction pressure

BW= water volume factor at pump suction pressure

20

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APPENDIX X

TABLE 04

Gravel size Gravel size Screen OpeningScreen Gauge

(US Mesh) (in. ) (in. ) (micron)

40/60 0.0165-0.0098 0.008 200 8

30! 50 0.0230-0.0120 0.010 250 10

20140 0.0330-0.0165 0.012 300 12

16/30 0.0470-0.0230 0.016 400 16

12120 0.0660-0.0330 0.020 -500 20

8/12 0.0940-0.0470 0.028 700 28

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