productions, decline, and ift analysis

HISTORICAL PRODUCTIONS ANALYSIS, DECLINE ANALYSIS AND INCREMENTAL CALCULATION OF CHEMICAL INJECTION TANJUNG FIELD ZONE C.

1. Productions Analysis

1.1. Historical Productions Data Before Injection

Figure I-1.Historical Production of Zone C Before Chemical Injection

From the figure above show that average oil rate of Zone C is 80 bbl/day on last production before chemicals injection, the oil cut is decline slowly from 0.14 until 0.04 on november 2012, and the water cut also increase until 96.48 % was reached on november 2012.

Figure I-2.Historical Production of Well T-027 Before Chemical Injection

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Oil rate of well T-027 is 13.09 bbl/day on november 2012 , the oil cut is decline slowly until reached 0.03 on november 2012, and water cut before chemical injection is 96.50 %.


Oil rate of well T-060 is 0.15 bbl/day on november , the oil cut is decline until reached 0.01 on november 2012, and water cut before chemical injection is 98.56 %.

Figure I-4.Historical Production of Well T-062R Before Chemical Injection



Oil rate of well T-062R is 21.12 bbl/day, the oil cut is decline slowly until reached 0.04 on november 2012, and water cut before chemical injection is 96.01 %.


Oil rate of well T-121 is 33.92 bbl/day, the oil cut is decline slowly until reached 0.03 on november 2012, and water cut before chemical injection is 96.69 %.

1.2. Historical Production Data After Chemical Injection

Figure I-6.Historical Production of Zone C After Chemical Injection



From the figure above show that surfactant + NaCl + Alkaline injection is start on december 2012, effect of chemical injection is monitor in well T-027, T-060, T-062R and also in well T-121. Chemical injection is caused oil cut is increase from 0.04 to 4.5 (4.45 %) during two month after chemical injection and slowly decrease until 3.4 during one year monitoring. The chemical injection effect is also caused dynamic fluid level increase during two month after chemical injection and decrease significantly on february until june, after that the dynamic fluid level was increased from july until march with average value 730 m. There no significant effect of chemical injection on water cut, before injection the water cut is 96.48 and after chemical injection water cut decreased just only 0.0012 % or 96.60 in value.

Figure I-7.Historical Production of Well T-027 After Chemical Injection

Chemical injection effect on well T-027 is show in figure I-7, from the figure is also show that chemical injection effect caused oil cut was increased 3 %, the oil cut of well T-027 before chemical injection is 0.03 % and after chemical injection the oil cut is increased until 3.2 %. Another effect of chemical injection is show on dynamic fluid level was significantly increased (on the above figure is show on black line).




Chemical injection effect on well T-060 is show in figure I-8, from the above figure is also show that chemical injection effect caused oil cut was increased 1.15 %, the oil cut of well T-060 before chemical injection is 0.15 % and after chemical injection the oil cut is increased until 1.3 %. Another effect of chemical injection is show on dynamic fluid level was significantly increased (on the above figure is show on black line).

Figure I-9.Historical Production of Well T-062R After Chemical Injection



In the figure above show that chemical injection effect on well T-062R, chemical injection effect caused oil cut was increased 3.96% on two month after injection, slowly decrease to 1.96% until november 2013 and increase until 3.95% during december until march. The dynamic fluid level is also increased on two month after chemical injection and slowly decrease during february until march.


In the figure above show that chemical injection effect on well T-121, chemical injection effect caused oil cut was increased 5.07% on two month after injection, slowly decrease to 2%-3.5% .The dynamic fluid level is also increased on two month after chemical injection and slowly decrease during february until march.



2. Chan's Diagnostic Analysis

Figure I-11.Chan's Diagnostic Analysis for Well T-027

Chan's diagnostic analysis conducted to analyze production problem in each monitoring well, in figure above show that in well T-027 have near wellbore water channeling, plot between WOR and WOR derivative versus cumulative days of production resemble with near wellbore water channeling that analyzed by Chan's.




Chan's diagnostic analysis conducted to analyze production problem in well T-060 have near wellbore water channeling, plot between WOR and WOR derivative versus cumulative days of production resemble with near wellbore water channeling that analyzed by Chan's.

Figure I-13.Chan's Diagnostic Analysis for Well T-062R




3. IFT Analysis

Figure I-15.Average IFT in Mixer

Figure I-16.Average IFT in Monitor Well



3. Decline Analysis Pattern (T-027, T-060, T-062R, T-121) Zone C

Figure I-17.Historical Production of Zone C (Pattern Only)

3.1 Chi-Square Test AnalysisBase on Chi-Square Test analysis decline for Zone C show that the type of decline is Hyperbolic with b = 0.5 and decline rate (Di = 0.03235). So the Base Line is calculate with hyperbolic type.


q=q i

(1+bDit )1b


Table I-1.Base Line Calculation for Zone C

b 0,5 SKENARIO 1

Di 0,032358595 BASE CASEt DAY Q Before Q FORECAST

Okt-12 1.827,54 1 Nop-12 2.048,43 2 Des-12 1.922,033 Jan-13 1.863,174 Feb-13 1.806,975 Mar-13 1.753,286 Apr-13 1.701,957 Mei-13 1.652,848 Jun-13 1.605,839 Jul-13 1.560,7910 Agust-13 1.517,6211 Sep-13 1.476,2212 Okt-13 1.436,4913 Nop-13 1.398,3414 Des-13 1.361,6915 Jan-14 1.326,4616 Feb-14 1.292,5917 Mar-14 1.259,9918 Apr-14 1.228,6119 Mei-14 1.198,3920 Jun-14 1.169,2721 Jul-14 1.141,2022 Agust-14 1.114,1323 Sep-14 1.088,0124 Okt-14 1.062,8025 Nop-14 1.038,4526 Des-14 1.014,94



Figure I-18.Base Line of Zone C Base on Chi-Square Test

3.2. Forecasting of Chemical Flood Injection.

Table I-2.Historical Production Data After Chemical Injection

Date Qo (bbl)Des-12 2.478,76Jan-13 2.430,60Feb-13 1.072,72Mar-13 1.269,32Apr-13 1.306,87Mei-13 1.347,95Jun-13 1.461,98Jul-13 1.461,85

Agust-13 1.275,18Sep-13 1.154,36Okt-13 1.187,89Nop-13 1.122,74Des-13 1.858,40Jan-14 2.053,07

Feb-14 1.523,07



Figure I-19.Actual Data Production Vs Base Line



3.3. Incremental Calculation.

INCREMENTAL CALCULATIONS

MONTHBASE LINE

SURFACTANTINCREMENTA

L

BOPM BOPM BOPM

Des-12 1.922,03 2.478,76 556,73

Jan-13 1.863,17 2.430,60 567,43

Feb-13 1.806,97 1.072,72 -734,25

Mar-13 1.753,28 1.269,32 -483,96

Apr-13 1.701,95 1.306,87 -395,08

Mei-13 1.652,84 1.347,95 -304,89

Jun-13 1.605,83 1.461,98 -143,84

Jul-13 1.560,79 1.461,85 -98,94

Agust-13 1.517,62 1.275,18 -242,44

Sep-13 1.476,22 1.154,36 -321,86

Okt-13 1.436,49 1.187,89 -248,59

Nop-13 1.398,34 1.122,74 -275,60

Des-13 1.361,69 1.858,40 496,71

Jan-14 1.326,46 2.053,07 726,60

Feb-14 1.292,59 1.523,07 230,49

TOTAL -671,49



productions, decline, and ift analysis

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