GNK

PERTAMINA E & P – PRABUMULIH REGION SUMATRA

PVT ANALYSIS

for

Well GNK-80

GUNUNG KEMALA FIELD SOUTH SUMATRA

Samples background: Well GNK-80, Pressurized Oil & Gas taken from

separator for PVT analysis Ambient Oil samples taken from separator for Complete

Oil analysis All Samples collected by PT. GEOSERVICES [LTD].

Geological & Laboratory Division in Jakarta.

Analysis ProgramNo. Method Samples No.

1Validity test of wellhead fluid; determination of saturation pressure of separator liquid at wellhead temperature.

Oil 2

2 Validity test of wellhead gas; opening pressurized cylinder at laboratory temperature Gas 2

3Compositional analysis of wellhead gas and liquid up to heptanes plus fraction, including determination of nitrogen and carbon dioxide as well as calculation of recombined fluid composition

OIL & GAS 1

4 Recombination of wellhead fluid at specified of GOR.

5Pressure-volume relationship of reservoir fluid at reservoir temperature, including saturation pressure determination, compressibility of oil above saturation pressure and two-phase volume, below saturation pressure

6Differential vaporization of reservoir fluid at reservoir temperature, and presentation of gas solubility and oil shrinkage data

7Determination of specific gravity and compressibility factor of liberated gas, at all points on deferential vaporization. Determination of density of the liquid phase

8Viscosity of liquid phase at reservoir temperature at several pressures from above reservoir pressure to atmospheric pressure.

9Separator test at four single-stage separator pressures [including 0 psig] at specified temperature to determine the effects of separator pressure on solution gas oil ratio, formation volume factor and stock tank oil gravity

10 Compositional analysis of separator gases from above separator test [four compositions]

11 Adjustment of recombined fluid to a specified GOR or saturation pressure

12 Complete oil analysis OIL 1

Well GNK-80 Laboratory Procedures Sample Validity

Validity checks were performed to ensure that the samples were representative separator fluids. The opening pressure of each gas sample and the bubble point pressure of each liquid sample, at separator conditions, were determined. The bubble point pressure tests on the separator oils were close. The separator oils were not adjusted The gas sample labeled 243588 and oil sample labeled IUS-066 were chosen for recombination by Pertamina.

Hydrocarbon Compositional Analysis of Separator Fluids Using a gasometer a volume of separator oil was flashed to atmospheric pressure. The equilibrium state between gas and oil at atmospheric pressure and temperature was maintained. The volume of liberated gas was then recorded to determine the gas oil ratio at equilibrium conditions. The compositions of both fluids were determined using chromatography. Finally, using the composition of both fluids and the GOR, the pressurized separator oil sample composition was calculated. Meanwhile the composition of the separator gas up to dedocanes plus, was determined by gas chromatography .

Laboratory Procedures Physical Recombination of Separator Fluids

The separator gas and oil samples were recombined using the gas to oil ratio, GOR, recorded at the time of sampling, in order to obtain the reservoir fluid for recombination analysis. This ratio was 933 SCF/BBL.

Using the GOR at sampling conditions the bubble point pressure was observed at 4052 psig at 250.0°F, which was higher than the reservoir pressure of 2665 psig at 250.0 °F. As requested by Pertamina the recombined reservoir fluid sample was then adjusted to 2665 psig at 250.0 °F. This recombine fluid was then used for further PVT analysis.

Pressure-Volume Relationships The recombined fluid was charged into the PVT cell and then heated to reservoir temperature, 250.0oF. Starting from a pressure of 6000 psig [single phase conditions] the cell’s pressure was reduced step by step. For each pressure step the volume of the total fluid was recorded. During this test the bubble point pressure was noted at 2665 psig.

Differential Vaporization Test

After the pressure volume relationships test the recombined fluid was used for the differential vaporization test.

The cell was re-pressurized to 6000 psig and stabilized to maintain the fluid is in oil phase. Seven pressure steps of 2400, 2000, 1600, 1200, 800, 400, 100 and 0 psig were used in a differential pressure depletion test.

Laboratory Procedures

The gas oil ratio was found to be 542 cubic feet gas at standard condition per barrel of residual oil at 60OF. The relative oil volume was found to be 1.342 barrels of saturated oil per barrel of residual oil at standard conditions

Viscosity of Recombined Fluid Viscosities of the recombined fluid as a function of pressure at reservoir temperature of 250.0OF were measured using a high pressure rolling ball viscosimeter The minimum value of the viscosity was found to be 0.765 centipoise, at the bubble point pressure, while the maximum value of 2.39 centipoises was measured at atmospheric pressure.

Single Stage Separator Test

The separator test was conducted to determine total gas oil ratio, stock tank oil gravity and oil formation factor as a function of variation of separator pressure, at separator temperature.

This test was performed at pressures of 200, 150, 100 and 50 psig and separator temperature of 100OF The separator test data were then used to adjust the differential vaporization results to the separator conditions

Summary of Results

Well GNK – 80 Sample Validity

PTG No.

CylinderNo.

Location Date Time

SeparatorConditions

LaboratoryConditions

SaturationConditions Volume

Water Recovered

CcPress psig

TempoF

Opening Press

psig

TempoF

BubblePoint psig

TempoF

OIL SAMPLES

1 IUS-067 Separator 17/03/11 10:15 42.7 122.5 - - 25 140.0 365

2 IUS-066* Separator 17/03/11 15:10 42.7 122.5 - - 40 140.0 240

GAS SAMPLES

3 289702 Separator 17/03/11 09:00 80 139 80 140.0 - - 0

4 243588* Separator 17/03/11 14:15 80 139 80 140.0 - - 0

= Samples selected for recombination

Well GNK – 80 Hydrocarbon Analysis Separator Product and Wellstream Calculation

Well GNK-80Properties

Well GNK - 80Hydrocarbon Analysis of Reservoir Fluid

Well GNK – 80Compressibility

VOLUMETRIC DATA

@ 250°F

Saturation Pressure (Psat) 2665 psig

Density at Psat 0.7522 gm/cc

Pressure Range Single-Phase

psig Compressibility

v/v/psi

6000 to 5000 10.13 E -6

5000 to 4000 11.78 E -6

4000 to 3000 13.97 E -6

3000 to 2665 15.86 E -6

Well GNK – 80Pressure Volume Relationship

Well GNK – 80Diferential Vaporization @ 250 oF

Well GNK – 80 Reservoir Fluid Viscosity @ 250 oF

Well GNK – 80 Separator Flash Analysis

Well GNK – 80 Hydrocarbon Analysis of GasFrom Pressure Stage of Separator Test




Well GNK – 80Differential VaporizationAdjusted to Separator Conditions

9.00E-06

1.00E-05

1.10E-05

1.20E-05

1.30E-05

1.40E-05

1.50E-05

1.60E-05

1.70E-05

2500 3000 3500 4000 4500 5000 5500 6000 6500

Pressure, psig

Well GNK – 80Single Phase Reservoir Fluid Compressibility @ 250 oF

Well GNK – 80Solution Gas/Oil Ratio @ 250 oF

0

100

200

300

400

500

600

0 500 1000 1500 2000 2500 3000

Pressure, psig

Well GNK – 80Relative Oil Volume @ 250 oF

1.000

1.050

1.100

1.150

1.200

1.250

1.300

1.350

1.400

0 500 1000 1500 2000 2500 3000

Pressure, psig

0.00

0.50

1.00

1.50

2.00

2.50

3.00

0 1000 2000 3000 4000 5000 6000 7000

Pressure, psig

0.010

0.015

0.020

0.025

0 500 1000 1500 2000 2500

Pressure, psig

Well GNK – 80Reservoir Fluid Viscosity @ 250 oF

0

100

200

300

400

500

600

0 500 1000 1500 2000 2500 3000

Pressure, psig

Differential VaporizationSeparator Test, 200 psig at 100 °FSeparator Test, 150 psig at 100 °FSeparator Test, 100 psig at 100 °FSeparator Test, 50 psig at 100 °F


1

1.05

1.1

1.15

1.2

1.25

1.3

1.35

1.4

0 500 1000 1500 2000 2500 3000

Pressure, psig

Differential Vaporization

Separator Test, 200 psig at 100 °F





Vap/liq mole frac 1.000 Critical Point

0

500

1000

1500

2000

2500

3000

3500

-200 0 200 400 600 800 1000 1200

Pre

ssur

e, p

sia

Phase EnvelopePhase EnvelopeGNK#80 Reservoir Recombination EOS = SRK PenelouxGNK#80 Reservoir Recombination EOS = SRK Peneloux

Temperature, °F

Well GNK – 80Phase Envelope

Well GNK – 80Complete Oil Properties

Well GNK – 80Oil Chromatography

Well GNK – 80Oil Chromatography [properties]

PERTAMINA EP-PRABUMULIH REGIONSUMATRA

prepared by:

PT. GEOSERVICES [LTD].Geological & Laboratory Services Division

Jl. Mesjid no. 17Petukangan Utara

Jakarta 12260Ph. 736 5365/66Fax. 584 6562

E-mail: [email protected]

Documents

GNK