Tools To Manage Gas/Condensate Reservoirs; Novel Fluid-Property Correlations on the Basis of Commonly Available Field Data
- Adriana P. Ovalle (M-I Swaco) | Christopher Peter Lenn (Schlumberger) | William D. McCain (Texas A&M University)
- Document ID
- Society of Petroleum Engineers
- SPE Reservoir Evaluation & Engineering
- Publication Date
- December 2007
- Document Type
- Journal Paper
- 687 - 694
- 2007. Society of Petroleum Engineers
- 4.6 Natural Gas, 5.6.1 Open hole/cased hole log analysis, 3.3.1 Production Logging, 4.1.9 Tanks and storage systems, 5.2 Reservoir Fluid Dynamics, 5.2.2 Fluid Modeling, Equations of State, 5.2.1 Phase Behavior and PVT Measurements, 5.8.8 Gas-condensate reservoirs, 4.1.2 Separation and Treating, 4.1.5 Processing Equipment
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Certain fluid properties are required for studies related to management of gas/condensate reservoirs or prediction of condensate reserves. Often these studies must begin before laboratory data become available, or possibly when laboratory data are not available. Correlations to estimate values of these properties have been developed that are based solely on commonly available field data.
These properties are the dewpoint pressure of the reservoir fluid, changes in the surface yield of condensate as reservoir pressure declines, and changes in the specific gravity of the reservoir gas as reservoir pressure declines. No correlations based solely on field data have been published for any of these properties.
The field data required are initial producing gas/condensate ratio from the first-stage separator, initial stock-tank liquid gravity in °API, specific gravity of the initial reservoir gas, reservoir temperature, and selected values of reservoir pressure.
The dewpoint pressure correlation is based on data of 615 samples of gas condensates with worldwide origins. The other two correlations are based on 851 lines of constant-volume-depletion data from 190 gas-condensate samples, also with worldwide origins.
Correlation equations for gas condensates based on readily available field data have been developed. The correlations can be used to predict dewpoint pressures, decreases in surface condensate yields after reservoir pressure has decreased below dewpoint pressure, and decreases in reservoir-gas specific gravity at reservoir pressures below dewpoint pressure.
A value of dewpoint pressure is essential data for any reservoir study. A reasonably accurate estimate of dewpoint pressure for a specific reservoir fluid is necessary in situations in which laboratory data are not available or before laboratory data are obtained. Laboratory measurements of dewpoint pressure and other gas properties of 615 gas condensates with worldwide origins were used to develop a dewpoint-pressure correlation based on initial producing gas/condensate ratio, initial stock-tank oil gravity, and specific gravity of the original reservoir gas. This is the first proposed dewpoint-pressure correlation that does not require some laboratory-measured quantity.
Estimation of decreases in producing yields after the reservoir pressure drops below the dewpoint pressure is necessary for accurate prediction of condensate reserves. The reduction in surface yields can be as much as 75% during the primary production of a gas condensate. This reduction must be taken into account in the prediction of ultimate recoveries of condensate. A surface-yield correlation has been developed that is a function of a selected reservoir pressure, initial stock-tank oil gravity, specific gravity of the original reservoir gas, and reservoir temperature. The data set included laboratory studies of 190 gas-condensate samples. This is the first proposal offered in petroleum literature of a correlation to estimate the decreases in surface yield.
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Breiman, L. and Friedman, J.H. 1985. Estimating Optimal Transformations forMultiple Regression and Correlation. J. of American StatisticalAssociation 80 (391): 580-619.
Dandekar, A.Y. and Stenby, E.H. 1997. Measurement of Phase Behavior ofHydrocarbon Mixtures Using Fiber Optical Detection Techniques. Paper SPE38845 presented at the SPE Annual Technical Conference and Exhibition, SanAntonio, Texas, 5-8 October. DOI: 10.2118/38845-MS.
Elsharkawy, A.M. 2001. Characterization of the Plus Fractionand Prediction of the Dewpoint Pressure for Gas Condensate Reservoirs.Paper SPE 68776 presented at the SPE Western Regional Meeting, Bakersfield,California, 26-39 March. DOI: 10.2118/68776-MS.
Engineering Data Book, Vol. II. 1987. 25.1-25.112. Tulsa: Gas ProcessorsSuppliers Association.
Gold, D.K., McCain, W.D. Jr., and Jennings, J.W. 1989. An Improved Method of theDetermination of the Reservoir-Gas Specific Gravity for Retrograde Gases.JPT 41 (7): 747-752. SPE-17310-PA. DOI: 10.2118/17310-PA.
Hall, K.R. and Yarborough, L. 1973. A New Equation of State for Z-FactorCalculations. Oil and Gas J. 71 (18): 82-92.
Humoud, A.A. and Al-Marhoun, M.A. 2001. A New Correlation for Gas CondensateDew-point Pressure Prediction. Paper SPE 68230 presented at the SPE MiddleEast Oil Show, Bahrain, 17-20 March 2001. DOI: 10.2118/68230-MS.
Lee, A.L., Gonzalez, M.H., and Eakin, B.E. 1966. The Viscosity of Natural Gases.JPT 18 (8): 997-1000. SPE-1340-PA. DOI: 10.2118/1340-PA.
Kleyweg, D. 1989. A Set ofConsistent PVT-Correlations for Gas/Condensate Systems. Unsolicited paperSPE 19509. DOI: 10.2118/19509-MS.
Marruffo, I, Maita, J., Him, J., and Rojas, G. 2001. Statistical Forecast Models toDetermine Retrograde Dew Pressure and C7+ Percentage of Gas Condensates onBasis of Production Test Data of Eastern Venezuelan Reservoirs. Paper SPE69393 presented at the SPE Latin American and Caribbean Petroleum EngineeringConference, Buenos Aires, 25-28 March. DOI: 10.21178/69393-MS.
McCain, W.D. Jr. 1990. The Properties of Petroleum Fluids, 2nd Ed.,374-385. Tulsa: PennWell Books.
Nemeth, L.K. and Kennedy, H.T. 1967. A Correlation of Dewpoint Pressurewith Fluid Composition and Temperature. SPEJ 7 (2): 99-104.SPE-1477-PA. DOI: 10.2118/1477-PA.
Niemstschik, G.E., Poettmann, F.H., and Thompson, R.S. 1993. Correlation for Determining GasCondensate Composition. Paper SPE 26183 presented at the SPE Gas TechnologySymposium, Calgary, 28-30 June. DOI: 10.2118/26183-MS.
Organick, E.I. and Golding, B.H. 1952. Prediction of Saturation Pressuresfor Condensate-Gas and Volatile-Oil Mixtures. Trans., AIME 195:135-148.
Piper, L.D., McCain, W.D. Jr., and Corredor, J.H. 1999. CompressibilityFactors for Naturally Occurring Petroleum Gases. Gas ReservoirEngineering 52:23-33. Richardson, Texas: SPE ReprintSeries.
Potsch, K.T. and Bräuer, L. 1996. A Novel Graphical Method forDetermining Dewpoint Pressures of Gas Condensates. Paper SPE 36919presented at the SPE European Petroleum Conference, Milan, Italy, 22-24October. DOI: 10.2118/36919-MS.
Rayes, D.G., Piper, L.D., McCain, W.D. Jr., and Poston, S.W. 1992. Two-Phase Compressibility Factors forRetrograde Gases. SPEFE 7 (1): 87-92. SPE-20055-PA. DOI:10.2118/20055-PA.
Rounce, J., Lenn, C., and Catala, G. 1999. Pinpointing Fluid Entries inProducing Wells. Paper SPE 53249 presented at the SPE Middle East Oil Show,Bahrain, 20-23 February. DOI: 10.2118/53249-MS.
Standing, M.B. and Katz, D.L. 1942. Density of Natural Gases. Trans.,AIME 146: 140-149.
Xue, G., Datta-Gupta, A., Valko, P.P., and Blasingame, T.A. 1997. Optimal Transformations for MultipleRegression: Application to Permeability Estimation from Well Logs.SPEFE 12 (2): 85-93. SPE-35412-PA. DOI: 10.2118/35412-PA.