Reservoir Fluid Study for OCCIDENTAL DE COLOMBIA Caño Rondon-1 Well, Form.: Mirador / K2A1 RFL 0603116 Core Laboratories Cra 39 Nro. 168-52, Bogotá, Colombia Tel: +57 (1) 6740400 Fax: +57 (1) 6730060 Web: http://www.corelab.com The analyses, opinions or interpretations in this report are based on observations and material supplied by the client to whom, and for whose exclusive and confidential use, this report is made. The interpretations or opinions expressed represent the best judgement of Core Laboratories Venezuela, S.A. (all errors and omissions excepted); but Core Laboratories Venezuela, S.A. and its officers and employees assume no responsibility and make no warranty or representations as to the productivity, proper operation or profitability of any oil, gas or any other mineral well formation in connection with which such report is used or relied upon.
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
The analyses, opinions or interpretations in this report are based on observations and material suppliedby the client to whom, and for whose exclusive and confidential use, this report is made. Theinterpretations or opinions expressed represent the best judgement of Core Laboratories Venezuela,S.A. (all errors and omissions excepted); but Core Laboratories Venezuela, S.A. and its officers andemployees assume no responsibility and make no warranty or representations as to the productivity,proper operation or profitability of any oil, gas or any other mineral well formation in connection withwhich such report is used or relied upon.
Two bottomhole samples and two wellhead samples from the subject well were collected onJuly 11th and July 12th of 2006 by Core Laboratories representatives and delivered to ourfluid laboratory in Bogotá for use in the performance of a Reservoir Fluid Study. Thesamples were transported to the laboratory whereupon sample validation and analysiscommenced.
Preliminary results were reported during the execution of the study and the final report ispresented in the following pages.
It has been a pleasure to perform this study for Occidental de Colombia. Should anyquestions arise or if we may be of further service in any way, please do not hesitate tocontact us.
OCCIDENTAL DE COLOMBIACaño Rondon-1 Well, Form.: Mirador / K2A1___________________________________________________________________________________________RFL 0603116
Table of Contents
Section A - Summary of PVT Methods and Data Page
Summary of analysis methods........................................................................................ A.1-A.3
Summary of PVT data..................................................................................................... A.4
Section B - Summary of Samples Received and Validation Data
Well information............................................................................................................... B.1
Summary of samples received ....................................................................................... B.2
Section C - Compositional Analysis of Wellhead Fluid Sample to C36+
Compositional analysis of wellhead fluid sample to C36+............................................... C.1-C.2
Section D - Constant Composition Expansion
Constant composition expansion at 238 °F..................................................................... D.1-D.2
Graphs from constant composition expansion at 238 °F................................................ D.3
Partial constant composition expansion at 120 °F.......................................................... D.4-D.5
Partial constant composition expansion at 86 °F............................................................ D.6-D.7
Partial constant composition expansion at laboratory ambient temperature (68 °F)....... D.8-D.9
OCCIDENTAL DE COLOMBIACaño Rondon-1 Well, Form.: Mirador / K2A1___________________________________________________________________________________________RFL 0603116
Summary of Analysis Methods
Sample ValidationThe bubble point pressure at ambient temperature and free water content of each wellhead samplewere determined as initial quality checks. From this quality control, the measured bubble pointpressures of the samples showed good agreement with one another and very little free water wasmeasured.
Heat TreatmentThe selected wellhead fluid sample was heated to 200°F prior to subsampling for laboratory tests toavoid potential wax deposition problems.
Pressurized Fluid CompositionApproximately 30 cc of pressurized fluid was flashed to atmospheric pressure at 120 °F andseparated into gas and oil phase. The evolved gas and residual liquid were analyzed separately,using gas-liquid chromatography and recombined on a weight basis to produce a C36+ weightpercent composition.
Gas CompositionsGas composition were measured using a "one shot" Varian 3800 gas analyzer using GPA 2286method. The gas chromatograph utilizes 3 columns to clearly identify all of the eluted componentsfrom N2, CO2 and C1 through C11+.
The chromatograph is calibrated weekly using air and synthetic hydrocarbon gas with a knowncomposition. The resultant calibration data is checked statistically against previous calibrationsprior to performing analyses on unknown samples.
Liquid CompositionResidual/stocktank liquid composition were measured using a Varian 3400 chromatograph. Thegas chromatograph utilizes a cold on column, "sandwich injection" technique to ensure that arepresentative sample is injected and swept onto the column. The sample is run twice; first theoriginal fluid and then fluid spiked with n-tetradecane. This allows the laboratory to take intoaccount any heavy end (C36+) losses that may have occurred during the chromatographic run, andmake an accurate correction prior to reporting the liquid composition. The data obtained from thegas chromatograph is in weight %. Calculations to mole% and the plus fractions properties aredescribed later.
The chromatograph for liquid samples is checked daily, using a gravimetric n-paraffin mixcontaining a range of pure components from C8 through C36 and a synthetic gas-oil mix (D2887)with known composition. The resultant calibration data is checked statistically against previouscalibrations prior to performing analyses on unknown samples.
OCCIDENTAL DE COLOMBIACaño Rondon-1 Well, Form.: Mirador / K2A1___________________________________________________________________________________________RFL 0603116
Summary of Analysis Methods (Continuation)
Calculation of Mole% Compositions and Plus Fraction PropertiesThe residue or stocktank liquid whole sample molecular weight and density are measured using acryscope and a PAAR densitometer respectively.
The mole% data is calculated using GPSA mole weight and density data, where individualcomponents are identified, from carbon dioxide through decanes. Katz and Firoozabadi data areused from undecanes through pentatriacontanes. The residue mole weight and density values arecalculated so that the pseudo average mole weight and density are the same as the measuredvalues. This can lead to anomalous residue mole weights and densities where the Katz andFiroozabadi values may not be suitable for the isomer groups detected.
Other alternatives are to use an assumed C36+ molecular weight and density value, use a linearextrapolation technique for components from C10 to C35 to calculate the C36+ properties or toutilise distillation analysis to produce a C11+, C20+ or C36+ residual oil fraction and physicallymeasure the molecular weight and density.
Constant Composition ExpansionA portion of the wellhead fluid sample was charged to a high pressure visual cell at ambientlaboratory temperature . A partial constant composition expansion was carried out during whichthe bubble point pressure at ambient temperature was determined. This process was repeated fortemperatures of 86°F and 120°F and finally the sample was thermally expanded to the reservoirtemperature for the complete constant composition expansion test. Pressure-volume data for thesingle phase and two phase fluid were also determined. The density of the single phase fluid wasdetermined by weighing measured volumes pumped from the cell at 5000 psig. Density data forother pressures were calculated using the volumetric data.
Differential VaporizationThis was carried out in a high pressure visual cell, at reservoir temperature. At several pressurestages below the observed saturation pressure, the sample was stabilized. The gases evolvedwere then pumped out of the cell and its volume, compressibility and gravities were determined.The final stage was carried out at atmospheric pressure when the residual liquid was pumped out ofthe cell and its volume, density and molecular weight were measured.
OCCIDENTAL DE COLOMBIACaño Rondon-1 Well, Form.: Mirador / K2A1___________________________________________________________________________________________RFL 0603116
Summary of Analysis Methods (Continuation)
Reservoir Fluid ViscosityLive-oil viscosity was measured in an electromagnetic viscometer at reservoir temperature.Viscosity determinations were carried out over a wide range of pressures from above the reservoirpressure to atmospheric pressure.
The measurements were repeated at each pressure stage until five or more results agreed to within0.5%. The densities, obtained from the constant composition expansion and differentialvaporization tests, were used in the calculation of viscosities in centipoise.
Separator TestsFinally, two single-stage separator tests were carried out using a pressurized test separator cell. Aportion of the bottomhole fluid sample, at a pressure above saturation pressure, was pumped intothe separator cell and stabilized at the pressure and temperature required for the first stageseparation. The gas evolved was pumped out of the cell and the volume and composition weredetermined. The final stage was carried out at atmospheric pressure and separator temperatureand the density of the residual liquid was determined.
Date sampled........................................................... 11-Jul-06 & 12-Jul-06Time sampled .........................................................Type of samples....................................................... Bottomhole & WellheadSampling company.................................................. Core LaboratoriesSampling Depth...................................................... 3,300 ft
Choke....................................................................... *Status of well............................................................ Shut-In
(1) Relative Volume = V / Vsat ie. volume at indicated pressure per volume at saturation pressure.(2) Instantaneous compressibility = (V2-V1) / V1 x 1/(P1-P2)
(1) Relative Volume = V / Vsat ie. volume at indicated pressure per volume at saturation pressure.(2) Instantaneous compressibility = (V2-V1) / V1 x 1/(P1-P2)
(1) GOR in cubic feet of gas at 14.70 psia and 60°F per barrel of residual oil at 60°F.(2) Volume of oil at indicated pressure and temperature per volume of residual oil at 60°F.(3) Volume of oil plus liberated gas at indicated pressure and temperature per volume of residual oil at 60°F.(4) Volume of gas at indicated pressure and temperature per volume at 14.70 psia and 60°F.
(1) GOR in cubic feet of gas at 14.70 psia and 60°F per barrel of oil at indicated pressure and temperature.(2) GOR in cubic feet of gas at 14.70 psia and 60°F per barrel of stocktank oil at 60°F.(3) Volume of saturated oil at 524 psig and 238°F per volume of stocktank oil at 60°F.(4) Volume of oil at indicated pressure and temperature per volume of stocktank oil at 60°F.
(1) GOR in cubic feet of gas at 14.70 psia and 60°F per barrel of oil at indicated pressure and temperature.(2) GOR in cubic feet of gas at 14.70 psia and 60°F per barrel of stocktank oil at 60°F.(3) Volume of saturated oil at 524 psig and 238°F per volume of stocktank oil at 60°F.(4) Volume of oil at indicated pressure and temperature per volume of stocktank oil at 60°F.
* ASTM Data Series Publication DS 4B (1991) - Physical Constants of Hydrocarbon and Non-Hydrocarbon Compounds.
** GPA Table of Physical Constants of Paraffin Hydrocarbons and Other Components of Natural Gas, GPA 2145-96.
*** Journal of Petroleum Technology, Nov 1978, Pages 1649-1655. Predicting Phase Behaviour of Condensate/Crude Oil Systems Using Methane Interaction Coefficients - D.L. Katz & A. Firoozabadi.
Note :The gas mole % compositions were calculated from the measured weight % compositions usingthe most detailed analysis results, involving as many of the above components as were identified.The reported component mole % compositions were then sub-grouped into the generic carbonnumber components.
* ASTM Data Series Publication DS 4B (1991) - Physical Constants of Hydrocarbon and Non-Hydrocarbon Compounds.
** GPA Table of Physical Constants of Paraffin Hydrocarbons and Other Components of Natural Gas GPA 2145-96.
*** Journal of Petroleum Technology, Nov 1978, Pages 1649-1655. Predicting Phase Behaviour of Condensate/Crude Oil Systems Using Methane Interaction Coefficients - D.L. Katz & A. Firoozabadi.
Note :The residue mole weight and density values ( eg heptanes plus, undecanes plus, eicosanes plus)are calculated so that the calculated average mole weights and densities correspond with themeasured values. This can lead to anomalous residue mole weights and densities where the Katzand Firoozabadi values may not be suitable for the isomer groups detected.