ANALISA PRESSURE BUILD UP TEST

OBJECTIVES

To understand basic principle of commonly performed pressure test; Build up and drawdown test with simple example of PBU & PDD analysis; The assumptions and limitations of the tests and demonstrate how to make interpretation from those test using package software in obtaining the Information from well testing.

1. Reservoir Pressure buildup curves can be extrapolated to obtain static reservoir pressure.

2. Permeability is a measure of the ability of the reservoir rock to transmit fluid flow. The permeability measured by a well test is the effective permeability of the reservoir rock for the produced fluid.

3. Transmissivity is a measure of the ability of the reservoir to transmit the fluid contained within it. It is a function of both reservoir rock and fluid properties.

4. Skin Factor is a quantitative measure of the degree to which the permeability in the immediate vicinity of the well bore has been altered as a result of the drilling, completion, and production process.

5. Damage Ratio is the ratio of the theoretical production rate to the actual production rate measured during the test. It is an indication of the degree to which the well's productivity can be improved by removing the skin damage induced during drilling and completion of the well.

6. Productivity During a test, the productivity of the well is measured at a flowing pressure that may or may not represent a reasonable producing pressure. The test results can be used to predict the productivity of the well at any desired flowing pressure.

Reservoir characteristics that can be calculated from a well test include, but are not limited to, the following:

INFORMATION GATHERED FROM WELL TEST

7. Radius of Investigation is the approximate radial distance from the well bore that is investigated by the test; the test analysis results represent the average properties of the reservoir within this radius.

8. Reservoir Anomalies within the radius of investigation include barriers and fluid contacts. Permeability changes or layered reservoirs are often reflected in the pressure behavior observed during a test. This information, when used in conjunction with other data, can often help in defining the exact type of anomaly.

9. Reservoir Depletion If an observable pressure depletion occurs during a test, then a small reservoir has been penetrated and most likely would not contain commercial quantities of hydrocarbons.

INFORMATION GATHERED FROM WELL TEST. CONT..

All well tests undergo a transient or infinite-acting radial flow period at some point in the test. As a result, an analysis technique based on this flow regime would be universally applicable as long as this flow regime could be recognized on the data. The following sections demonstrate how to recognize and analyze this flow regime.

When a well is opened to flow for a drawdown test or shut in for a buildup, a pressure gradient, or transient, is established between the well bore and the reservoir. This pressure transient propagates into the reservoir at a speed that is directly dependent on the reservoir's rock and fluid properties.

PRINCIPLE OF DRAWDOWN AND BUILDUP TRANSIENTS

PRESSURE TRANSIENT PROPAGATION IN A RESERVOIR

FLOW REGIME CATEGORIES

PRESSURE BUILD UP TEST

Pressure buildup testing is the most familiar transient well-testing technique, which has been used extensively in the petroleum industry. Basically, the test is conducted by producing a well at constant rate for some time, shutting the well in (usually at the surface), allowing the pressure to build up in the wellbore, and recording the down-hole pressure in the wellbore as a function of time.

From these data, it is possible to estimate the formation permeability and current drainage area pressure, and to characterize damage or stimulation and reservoir heterogeneity or boundaries frequently.

In an ideal situation, we assume that the test is conducted in an infinite acting reservoir in which no boundary effects are felt during the entire flow and later shut-in period. The reservoir is homogeneous and containing in aslightly compressible, single-phase fluid with uniform properties. Wellbore damage and stimulation is concentrated in a skin of zero thickness at the wellbore. Flow into the wellbore ceases immediately at shut-in.

If a well is shut-in after it has produced at rate q for time tp and the bottom-hole pressure pws is recorded at time dt, then a plot of pws versus log (tp –dt)/dt will give a straight line, which is represented by the following equation:

; and the skin factor :

A. IDEAL PRESSURE BUILD UP

EXAMPLE : Ideal Pressure Build Up

6. Read original reservoir pressure pi = 1960psia.

IDEAL PRESSURE BUILDUP GRAPH.

B. ACTUAL PRESSURE BUILD UP

Early-time region (ETR). In this region, a pressure transient is moving through the formation nearest the wellbore.Middle-time region (MTR). In this region, the pressure transient has moved away from the wellbore into the bulk formation.Late-time region (LTR). In this region, the pressure transient has reached the drainage boundaries well.

TECHNIQUE FOR ANALYZE PBU TEST

Well bore Storage is caused when the flow rate at the wellhead is different than the flow rate at sandface. It is usually caused by well bore unloading, After flow Analysis, or changing fluid levels. Data affected by well bore storage effects contain little or no information about the reservoir.

WELLBORE STORAGE

WELLBORE STORAGE /AFTER FLOW

EXAMPLE Analyzing Single-Phase and Single-Rate Pressure Buildup Test

A single-phase and single-rate pressure buildup test was conducted on an oil well. The data is given in Table. The following well/reservoir parameters are given: Bo = 1.224 rb/stb, h = 55 ft, Poro = 0.06, rw = 0.21 ft, co = 1.5 x 10-6, and Viso = 0.65 cP, psc = 14.65 psia, T = 2000F, re = 1520ft, and Rho0 = 53.51bm/ft3.Assume the well is draining from the center of a square. Well depth = 4500 ft, q/ = final production rate at shut-in time = 250 stb/day, and cumulative production at shut-in time = 141,979 stb.

1. At what shut-in time At does afterflow cease and boundary effect appear? 2. Formation permeability, k 3. Skin factor, s 4. Additional pressure drop near the wellbore, (Ap)skin 5. Effective wellbore radius, rwa 6. Flow efficiency FE using p* 7. Damage ratio DR using/?* 8. Productivity index, PI 9. Radius of investigation by the shut-in transient at the start and end of the MTR10. End of wellbore storage distortion.

Determine the following:

SOLUTION

1. Estimate the pseudo-producing time, tp,

2. Determine end of wellbore storage, time at beginning MTR and end of MTR

From the semilog graph, seems afterflow distortion disappears at (tp+dt)/dt = 2280 or dt = 6.25 hours, because of the end of the S-shaped characteristic curve.

p1hr = 4295psia and p* at (tp + dt)/dt = 4577psia

3. Determine p1hr and p*

4. Determine permeability

5. Determine other parameter s, dPskin, rwa, FE, DR, PI, rinv.

Log-log single-rate buildup data plot.

Semilog single-rate buildup data plot.

A computational model that describes the relationship between the pressure, flow rate and reservoir rock and fluids properties In its simplest form is the diffusivity equation for a well in the center of a circular, homogeneous, horizontal reservoir, uniform thickness and a 1 phase fluid that obeys Darcy's law.

COMPUTATIONAL MODEL

The actual reservoir model is constructed from the basic equation but take into account the geometry of the reservoir (radial, linear, elliptical or spherical), number and types of fluids and the flow regime.

The flow geometry for that area affected by the test can be the most common model used to represent the pressure behavior of the reservoir is radial flow, where all flow occurs radially toward the well between impermeable upper and lower boundaries at a constant surface flow rate. The interpretation of test data will yield average reservoir properties even when reservoir heterogeneities exist.

While the equation cannot be solved directly, indirect techniques provide a satisfactory estimate using numerical computation.

1. Identification of the proper model for the classification of the reservoir (finite, infinite, homogeneous, dual porosity, dual permeability, skin, fractures).

2. Specific analysis and calculations to estimate well and reservoir characteristics.

3. Verification of results to ensure that the process resulted in the best answer.

WELL TEST DATA INTERPRETATION

There are three major steps to a unified approach to well test data interpretation:

Well test interpretation is based on patterns of pressure change and the derivative of pressure change to identify the type of reservoir behavior.

1. Use a Diagnostic graph. A diagnostic graph is a plot of the pressure change and the derivative of the pressure change versus time on log-log paper. It can be used to identify each flow period. Behavior specific plots can be useful to identify heterogeneous behavior, effects of wellbore storage and high and low conductivity fractures

2. Calculate basic reservoir parameters, such as the kh, skin and well bore storage capacity. This can be done conventionally, through the use of specific plots, or with type curves.

3. Compare the result from well to well and from time to time with the same well for matching or method is to prepare and analyze a dimensionless semi-log plot .

4. Used calculated parameters as input simulator and run to see if it matches the input data.

AN EFFECTIVE WAY TO INTERPRET PRESSURE DATA

CASE STUDY PRESSURE BUILD UP TEST

WELL : ASDJ-73

TEST DATE : 26-30 MAY 2007

FLOW and PRESSURE BUILD UP PROGRAM ASDJ-73

REVISION #1

I. Technical Data: Area : Central Air Serdang Well Status : Producing- Flowing oil. GL : 50.961 m KB : 55.176 m Total Depth : 1650.00 mKB SurfaceCasing : 13 3/8” 54.5 ppf. K 55 BTC R 3 set at 54.00 mKB Intermediate Casing : 9 5/8” 40 ppf. K 55 BTC R 3 at 845.00 mKB Production Casing : 7” 23 ppf. K 55 BTC R 3 at 1635.00 mKB Tubing : 2 7/8” 155 jts, Top of Firing Head and perf.gun at 1523.85 mKB F nipple at 1480.01 mKB Packer : 7” PR-3 set at 1483.10 mKB Perforations : 1529.50 – 1536.50 mKB (BRF) Reservoir Pressure : 2000 Psi - estimated. Reservoir Temp : 250 deg F- estimated Current production : Test May 20- 909 blpd, WC 6 %, 853 bopd. WHP 400 Psi, FLP

170 Psi. II. Objective:

1. To measure formation productivity 2. To measure Static Reservoir Pressure 3. To evaluate/estimate Reservoir Properties and characteristics

I. Procedure: 1. Shut-in the well at the Flowline and Master Valve. 2. Rig up Wireline unit with 2 7/8” tubing Gauge Ring, Sinker Bars and Lubricator as per

Talisman Spec. Pressure Test the lubricator. 3. Slowly open the Master Valve and pressure up the lubricator. 4. RIH Gauge Ring and sinker bar to top F nipple at 1480.01 mKB. POOH 5. Shut-in the well. 6. Rig up Tandem Pressure and Temperature Recorders set for a minimum 240 hrs clock

time. Recorder Sample Rate is 3 minutes for the first 50 hours, 1 minute for the next 4 hours, then 3 minutes for the remainder of clock time.

7. Slowly Open the well to the Block Station Test facilities and flow the well on 20% Choke (same as prior to Shut-in) for 2 hours before running Pressure Recorders and 48 hours after the Pressure Recorders are landed at the F nipple. Record with DWG the Tubing, Casing and Flowline pressure every hour for the duration of the test.

8. Flow the well for 2 hours before starting run in hole with the Recorders. 9. RIH recorders while flowing to the Block Station. Record flowing pressure &

temperature at depth 100, 200, 300, 400, 500, 600, 750, 900, 1050, 1200, 1350 and 1400 mKB for 5 minutes each. Land the Recorders in or below the F Nipple at 1480 mKB. Secure the recorders and wireline equipment.

10. Take Deadweight Gauge pressures on the Tubing, Casing, Flowline pressure every hour for the duration of the test.

11. Record the Production Test data (Flow, Pressures, Water Cut, Gas rate etc.) every 1 hour for the duration of the 50 hour Flow Test.

12. After the 50 hrs flow, Shut-in the well for 72 hrs PBU. Record casing and tubing pressure with DWG every hour for the duration of the PBU.

13. At the end of the 72 hour build up, conduct a Static Gradient when pulling the Recorders out of the hole as follows. Record pressure and temperature at depth 1450, 1400, 1350, 1200, 1050, 900, 750, 600, 500, 400, 300, 200, 100 mKB and Surface for 7 minutes each.

14. Report all the test data to reservoir engineering at Jakarta Office. Note :

Safety is Priority #1. Check all Emergency Shutdown system and function test the equipment before the job. Flare to be ready Confirm data acquisition is up and running before running in hole.

Jakarta, May 22, 2007 Revised by : Mark Soper and Artono Approved by : Arif Prabawa. Operation Manager. Distribution : 1-Field Operation Air Serdang. 2-BBS Jakarta

STRUCTURAL LOCATION 89ok-48

ASDJ-73X (Main Target BRF)ASDJ-73X (Main Target BRF)

Top Baturaja Fm.Depth Structure Map

C.i : 2 m

ASDJ-73X

95ok

-07

OWC 1514 mss

OWC

1514

m

ss

89ok-48

ASDJ-73X (Main Target BRF)ASDJ-73X (Main Target BRF)

Top Baturaja Fm.Depth Structure Map

C.i : 2 m

ASDJ-73X

95ok

-07

OWC 1514 mss

OWC

1514

m

ss

PORO > 22%BRF DEPTH STRUCTURE MAP

OW

C 1

514

mss

Air Serdang Field

TOP BRFDepth Structure Map

C.I: 2 m

SEISMIC ~ Lateral continuity

ASDJ-73

BRF Perforation :1529.5-1536.5m

H = 9 m ; Poro = 25 %PERM = < 10 Md ; SW = 20 %Perforation = 7 m ; API = 31

FMC GL: 50.961 m JOB PERTAMINA-TALISMAN (OK) LTD.KB: 55.176 m.

ESP Elect.

Cable.

3-2 7/8" PJ13-3/8" Csg K-55,54.5#BTCR-3 Set @ 54 m

9 5/8" Csg, 40 ppf, K-55BTC, R-3, Set @ 845.0 m

152 Jts. 2-7/8" Tbg.

Marker PJ ( 3.12 m )1-27/8" tbgF-nipple2 7/8" PJPR-3 pkr

2-2 7/8" tbg

CCSV2-2 7/8" tbg

Drop-bar Firing-headSafety-spacerPerf.gun 5 1/2"

Perf. BRF 1529.50 - 1536.50 mBull-nose

7" Saga BP ( 1580 m )

Perf TAF 1601-1605 M 7" Csg. 23ppf, K55, BTC,R-3

Set @ 1635 mTD 1650 m.

WELL CONDITIONS

1. Get Stuck (slow pumping for ± 18.5 hrs) caused by DW-transmission broken while drilling @1598m before free after 235 x jarring.

2. Partial loss ± 62 Bbl while circ for 7” cementing.3. Flow without swabbing after perforation with TCP.

HOURS6.00 Prepare and M/U TCP 4-1/2" TCP Gun 5 spf, 72° phase, Hyper Jet 4505 RDX charges P/N 447660

7" R-3 Packer, PJ, R-Npl, 20 Jts 2-7/8" Tbg, (fill Tbg w/ 1 bbl produce water) to 1536.5 m2.501.501.50 Schlumberger RIH GR-CCL confirmation of perforation depth (on depth), R/D wireline equipment1.00 N/D 7-1/16" BOP's, N/U X-Tree, Drop bar to fire TCP gun BRF interval 1529.5-1536.5 m - ok.1.500.50

12.50Shut in well, installed chicksan fr/ X-Tree to Flow lineSwitched Production test to Block station Pt = 300 psi, Pf = 150 psi.

R/U Schlumberger equipment & RIH GR-CCL to coralate of perforation depth.Space out string (Added 8 m Pup Joint), set packer w/ 12,000 lbs compress.

Observed well, the well flow air to follow liquid to swab tank.

COMPLETION DATE MAERCH 03, 2007

Note :

OIL (BBL/D)

GAS (MSCF/D)

WATER (BBL/D)

Liquids (BLPD)

OIL (BBL) GAS (MSCF)WATER

(BBL) DAYS

Mar-07 29 844 364 47 891 24,475 10,570 1,352 29

Apr-07 30 890 417 58 948 51,186 23,071 3,090 59

May-07 29 847 454 54 901 75,738 36,229 4,658 88

TOTAL 88 860 412 53 913 75,738 36,229 4,658 88

March 3, 2007 produce in BRF

DAYS ON PROD.

CUMMULATIVE

MONTH

AVERAGE PRODUCTION

WELL PERFORMANCE

TEST RESULT SUMMARY

Date : 24 May (18.00) – 30 May 2007 (18.00)Flow time : 50 hrs.Built up time : 92.42 hrs.Gauge Depth : 1501 m (4924 ft)

Production Rate : 859 BOPD / 581 MCFD / 56 BWPDFlowing Pressure : 1181 psi @1533m (mid perforation)Flowing Gradient : 0.152 psi /ft. ~ Average (slug flow)Static Pressure : 1659 psi @1533m (mid perforation)Static Gradient : 0.1338 psi /ftLiquid Gradient : 0.3159 psi /ftLiquid Level : ± 900 m.

Productivity Index : 2.13 BPD/PSIQ max : 2,015 BPD (1990 BOPD)

: 1,900 BOPD

Field : AIR SERDANG Perforation Interval : 5018.29 - 5041.257 FT RTWell No. : ASDJ73 1529.5 - 1536.5 m

DATE : IPR CALCULATION DESIGNDATA :Mid Perf : 5030 RT Pr : 1658 psi Pumpset : - RT 00 mSFL : 569 RT Pwf : 1181 psi Q : 913 bfpdWFL : 1855 RT PI : 2.13 bfpd/psi Pwf : 1181 psiRate : 913 bfpd Qb : 124 bfpd WFL : 1855 RT 565 mwatercut : 6 % Qmax : 2016 bfpd FAP : -1855 ft -565 mPb : 1600 psi 1895.237 oil 860 bopdoil 860 bopd Q<Qb

IPR tableQ (bfpd) Pwf (psi) WFL ('RT)

0.0 1658.4 569.5428.1 1451.1 1127.0807.4 1243.8 1684.51135.9 1036.5 2242.11413.6 829.2 2799.61640.5 621.9 3357.21816.5 414.6 3914.71941.8 207.3 4472.22016.2 0.0 5029.8

26/5/2007

IPR curve

0

200

400

600

800

1000

1200

1400

1600

1800

0 500 1000 1500 2000 2500

Q (bfpd)

Pwf (

psi)

PRESS GRADMETER FT PSI PSI/FT

- - 870 0100 328 876 0.0180200 656 893 0.0527300 984 901 0.0259400 1,312 910 0.0253500 1,641 918 0.0256600 1,969 926 0.0250750 2,461 938 0.0244900 2,953 986 0.0971

1,050 3,445 1144 0.32141,200 3,937 1301 0.31861,350 4,429 1456 0.31471,400 4,593 1507 0.31211,450 4,757 1558 0.31271,480 4,856 1618 0.6004

DEPTH

STATIC PRESSURE ASDJ73 BRF

500

750

1,000

1,250

1,500

500 750 1000 1250 1500 1750

PRESS (PSI)

DEP

TH (M

)

STATIC FLUID LEVEL ~ 900M

PRESSMETER FT PSI PSI/FT KSC/10M

- - 393 0.000100 328 550 0.479 1.105200 656 594 0.134 0.309300 984 630 0.108 0.249400 1,312 674 0.134 0.310500 1,641 742 0.208 0.481600 1,969 815 0.222 0.513750 2,461 892 0.156 0.360900 2,953 974 0.166 0.384

1,050 3,445 1,060 0.176 0.4051,200 3,937 1,090 0.061 0.1401,350 4,429 1,119 0.060 0.1381,400 4,593 1,156 0.226 0.5201,450 4,757 1,156 0.000 0.000

GRADDEPTH

STATIC PRESSURE ASDJ73 BRF

PRESS (PSI)

DEP

TH (M

)

FLOWING PRESSURE ASDJ73 BRF

500

750

1,000

1,250

1,500

500 750 1,000 1,250 1,500

PRESS (PSI)

DEP

TH (M

)

FLOWING & STATIC PRESSURE

SLUG FLOW ~ Pwf : 1181 PSI

BU ANALYSIS

Model : Rectangular, 3 side infinite acting. 1 No flow boundary, Vertical well, Partial

perforation, Dual porosity with Wellbore storage.

Avg eff. Permeability : 276 mDKh : 8150 md.ftSkin (Total) : 26.2Skin partial perforation : 0.581Skin damage : 19.93dP due to skin : 360 psi.Storativity ratio : ± 0.3Interporosity flow : 3.8.e-6P* : 1700 psi @1603m

Flow efficiency : 0.307PI actual : 1.718 bbl/d/psi.PI Ideal : 5.301 bbl/d/psi.

Radius of Investigation : 233 – 265 m.

RADIUS OF INVESTIGATION 89ok-48

ASDJ-73X (Main Target BRF)ASDJ-73X (Main Target BRF)

Top Baturaja Fm.Depth Structure Map

C.i : 2 m

ASDJ-73X

95ok

-07

OWC 1514 mss

OWC

1514

m

ss

89ok-48

ASDJ-73X (Main Target BRF)ASDJ-73X (Main Target BRF)

Top Baturaja Fm.Depth Structure Map

C.i : 2 m

ASDJ-73X

95ok

-07

OWC 1514 mss

OWC

1514

m

ss

PORO > 22%BRF DEPTH STRUCTURE MAP

OW

C 1

514

mss

Air Serdang Field

TOP BRFDepth Structure Map

C.I: 2 m

Ri ~ 770 ft

ASDJ73 48 HRS FLOW TEST BEFORE BU 24-26 MAY 2007

0

200

400

600

800

1000

1200

0 10 20 30 40 50 60

HOURS

50

55

60

65

70

75

80

BW

PD

BOPD MCFD BLPD BWPD

1.0 101 1023 4 5 6 7 8 9 2 3 4 5 6 7 8 9 2 3 4 5 6 7 8 2 3

t , h

1.0

101

102

103

2

34

68

2

34

68

2

34

68

p

/ Der

ivat

ive

, psi

TypecurveSITP ASDJ73 84 HOURS

p / DerivativedataDerivativedata

SHUT-IN WHP MONITORING

STRIP CHART BU ASDJ73 BRF 24-30 MAY 2007

10-2 10-1 1.0 101 1022 3 4 5 6 7 8 2 3 4 5 6 7 8 2 3 4 5 6 7 8 2 3 4 5 6 7 8 2 3

Real Time , h

10-1

1.0

101

102

103

104

58

2

47

2

47

2

47

2

47

2

47

p

/ Der

ivat

ive

, psi

TypecurveDiagnostic Analysis PBU ASDJ73 BRF

p / DerivativedataDerivativedata

t 92.05 hp 1659.0 psirinv 918.985 ft

t 0.17 hp 1456.4 psi

Storage 1C 0.05 bbl/psiCD 282.59

Radial 0k 277.854 mds' 25.555p* 1678.1 psi

t 13.57 hp 1642.0 psirinv 359.107 ft

MODEL PARAMETER

PARTIAL PERFORATION MODEL BU ASDJ73 BRFk = 276.007 mdsd = 19.934

Plan View(Not to scale)

No Flow

Y w =

183

Infinite Infinite

Infin

ite

Side View(Not to scale)

No Flow Top of Reservoir

No Flow Bottom of Reservoir

h =

29.5

28 ft

htop = 3.281 ft

hp = 22.966 ft

PARTIAL PERFORATION MODEL BU ASDJ73 BRFk = 276.007 mdsd = 19.934

Plan View(Not to scale)

No Flow

Y w =

183

Infinite Infinite

Infin

ite

Side View(Not to scale)

No Flow Top of Reservoir

No Flow Bottom of Reservoir

h =

29.5

28 ft

htop = 3.281 ft

hp = 22.966 ft

PRESSURE BUILD UP ANALYSIS

10-2 10-1 1.0 101 1022 3 4 5 6 7 8 2 3 4 5 6 7 8 2 3 4 5 6 7 8 2 3 4 5 6 7 8 2

Real Time , h

1.0

101

102

103

3

57

23

57

23

57

23

57

23

p

/ Der

ivat

ive

, ps

i

TypecurvePARTIAL PERFORATION MODEL BU ASDJ73 BRF

p / Derivativedatap / DerivativemodelDerivativedataDerivativemodel

pi (syn) 1703.5 psip* 1700.5 psiCumoil 77.54 Mbbl

kh 8149.80 md.fth 29.528 fthp 22.966 ftk 276.007 mdkh/kv 0.100s' 26.210sPP 0.581sd 19.934pskin 367.2 psiPIActual 1.680 (bbl/d)/psiPIIdeal 5.185 (bbl/d)/psi

t 92.42 hp 1659.2 psirinv 769.165 ft

Pressure History_(by well)BRF (CTR) ASD

0

250

500

750

1,000

1,250

1,500

1,750

2,000

2,250

2,500

2,750

3,000Ja

n-89

Jan-

90

Jan-

91

Jan-

92

Jan-

93

Jan-

94

Jan-

95

Jan-

96

Jan-

97

Jan-

98

Jan-

99

Jan-

00

Jan-

01

Jan-

02

Jan-

03

Jan-

04

Jan-

05

Jan-

06

Jan-

07

Jan-

08

Date

Pres

sure

(PSI

)ASD-2 ASD-3 ASD-4 ASD-6 ASD-7 ASD-8 ASD-9 ASD-10 ASD-11ASD-16 ASDJ-1 ASDJ-2 ASDJ-3 ASDJ-4 ASDJ-5 ASDJ-7 ASDJ-8 ASDJ-9ASDJ-10 ASDJ-11 ASDJ-12 ASDJ-14 ASDJ-15 ASDJ-16 ASDJ-18 ASDJ-37 ASDJ-47ASDJ-48 ASDJ-52 ASDJ-53 ASDJ-70 ASDJ-73

PRESS @DATUM (-1528MSS) : 1765 PSI.

CONCLUSION

1. ASDJ73 was act as production well in infinite acting reservoir along radius of investigation (233-265)m.

2. Barier may exist at one side of ASDJ73, probably at the western directions.

3. ASDJ73 has reservoir pressure ± 1765 psi; almost the same with current Central BRF Pressure (reservoir connect to existing depletion of BRF ASD).

4. Dual porosity works at the reservoir with enough large of fissures /fractures as storativity ratio ± 30%.

5. Reservoir has good average effective permeability (276 mD); Poor vertical permeability (Kh/Kv normal ~ 0.1) and High Productivity Index ( 5.2 bbl/d/psi).

6. Positive skin (+) 26 reduced the PI till 1.7 bbl/d/psi. Almost caused by wellbore damage. (Skin by perforation is only +0.5). Pressure loss due to skin is ± 367 psi.

7. High production rate of ASDJ73 almost caused by gas driven as static fluid level is only ± 900m (± 700 m liquid colum). Well produced under ± 480 psi drawdown (27%).

SPUD DATE :

HOLE (") : 8 1/2TIME BREAKDOWN (00:00 - 24:00)

HRS O P E R A T I O N

5.50 DF f/ 1505 to 1531 m0.50 Circ for cutting observation ( Top BRF @ 1530 m )

12.50 Cont'd DF to 1598 m, yoke of the propeller main-transmission of DW - broken ( DW no fungtion,string live static / can't move or rotate )

14.50 Repair on DW-transmission while slow circulationEstimate Top BRF @ 1530 mTop TAF-Shale @ 1583 mTop TAF-Sand @ 1596 m

4.00 Tried move the string, got stuck. Attemted for get free the stuck by jars-job w/ max OP 100,000 #( after jaring-up on 155 times, the jars work in proferly / good working ). On 235 times jaring thestring got free. Circ for cleaning hole w/ working in string

8.00 Wiper-trip to 9 5/8" csg-shoe for hole condition after stuck ( tight-hole @ 1530 m w/ OP 30,000 #when POOH and @ 1560 m tagged 15,000 # when RIH back )

15.50 Cont'd DF f/ 1598 to 1650 m;Circ hoie cleaning;Wipper-trip to 9 5/8" shoe1.75 Circ, deviation survey = 5 1/2 o ,swift hole by hi-vis mud, circ and drop 30 bbls hi-vis mud in bottom.6.25 POOH bit # 4 to surface5.00 Logging DLL-MSFL-GR-SP-LDL-CNL-BHC-Cal by Slb7.00 M/U and RIH 8 1/2" bit to 1650 m.2.00 Circ hole cleaning, spot 30 bbls hi-vis mud in bottom, re-survey for deviation = 5 1/2 o

9.00 POOH the 8 1/2" bit while L/D all drilling-string. Slack-off 5 1/4" kelly14.50 Prepared & RIH 7" csg to 1648 m csg-shoe and FC @ 1635 m ( BC @ 508, 901 and1204 m )1.50 Instaled cementing-head. Circulation, partial loss 0.5 - 0 bbls / mnt ( total mud loss = 62 bbls )1.00 Load btm & top-plug in cementing-head. Held safety meeting. Flush line and test to 2000 psi2.00 Pump 30 bbls spacer-fluid SP-01. Drop btm-plug, mix and pump 94.7 bbls cement-slurry of

15.2 ppg ( 214 sx cmnt G ). Drop top-plug, displace w/ 211 bbls fresh-water, bumping pressure2000 psi. Hold for 5 mnts, bleed off pressure - fluid back 1.5 bbls, float in function. Job complete

9.00 L/D 5 1/4" kelly, swivel and floor accessoriesPick-up 13 5/8" BOPs, set 7" csg-hanger, rough cut 7" csg excess, N/D 13 5/8" BOPs. Finnal cut7" csg, N/U section-B WH ( tbg-spool ). Test seal w/ 2500 psi - good. N/U x-treeRig released Jan 24, 2007

DRILLING HISTORY.

MUD PROPERTIES TOTAL MUD TANK VOLUME (bbls) = 340 MUD DUMPED (bbls) = 0MUD TYPE TIME = 12.00 YP = 8 Tot. Sol. % = 6 Mf = 1.2KCL PHPA DEPTH = 1650 PV = 6 MBT = - Cl = 28,000

FL temp = Gel = 3/7 Sand % = 0.2 Ca = 160Samp. loc MW = 9.6 pH = 10 K+ = 30,000 RPM600/300 = 0(in / out) Visc. = 35 FC = 1 PM = 0.6 RPM 200/ 100 = 0

WL = 8 HTHP = Pf = 0.6 RPM 6 / 3 = 0

Cont'd RIH 7" csg to 1648 m csg-shoe and FC @ 1635 m ( BC @ 508, 901 and1204 m )Instaled cementing-head. Circulation, partial loss 0.5 - 0 bbls / mnt ( total mud loss = 62 bbls )Load btm & top-plug in cementing-head. Held safety meeting. Flush line and test to 2000 psiPump 30 bbls spacer-fluid SP-01. Drop btm-plug, mix and pump 94.7 bbls cement-slurry of15.2 ppg ( 214 sx cmnt G ). Drop top-plug, displace w/ 211 bbls fresh-water, bumping pressure2000 psi. Hold for 5 mnts, bleed off pressure - fluid back 1.5 bbls, float in function. Job completeL/D 5 1/4" kelly, swivel and floor accessoriesPick-up 13 5/8" BOPs, set 7" csg-hanger, rough cut 7" csg excess, N/D 13 5/8" BOPs. Finnal cut7" csg, N/U section-B WH ( tbg-spool ). Test seal w/ 2500 psi - good. N/U x-treeRig released