Computer simulation of production from geopressured-geothermal aquifers. Project 61025 annual report, October 1, 1978-September 30, 1979
In the Department of Energy test of the Edna Delcambre No. 1 well for recovery of natural gas from geopressured-geothermal brine, part of the test producted gas in excess of the amount that could be dissolved in the brine. Where this excess gas originated was unknown and several theories were proposed to explain the source. This annual report describes IGT's work to match the observed gas/water production with computer simulation. Two different theoretical models were calculated in detail using available reservoir simulators. One model considered the excess gas to be dispersed as small bubbles in pores. The other model considered the excess gas as a nearby free gas cap above the aquifer. Reservoir engineering analysis of the flow test data was used to determine the basic reservoir characteristics. The computer studies revealed that the dispersed gas model gave characteristically the wrong shape for plots of gas/water ratio, and no reasonable match of the calculated values could be made to the experimental results. The free gas cap model gave characteristically better shapes to the gas/water ratio plots if the initial edge of the free gas was only about 400 feet from the well. Because there were two other wells at approximately this distance (Delcambre No. 4 and No. 4A wells) which had a history of down-hole blowouts and mechanical problems, it appears that the source of the excess free gas is from a separate horizon which connected to the Delcambre No. 1 sand via these nearby wells. This conclusion is corroborated by the changes in gas composition when the excess gas occurs and the geological studies which indicate the nearest free gas cap to be several thousand feet away. The occurrence of this excess free gas can thus be explained by known reservoir characteristics, and no new model for gas entrapment or production is needed.
- Research Organization:
- Institute of Gas Technology, Chicago, IL (United States)
- DOE Contract Number:
- AC08-78ET27098
- OSTI ID:
- 5308413
- Report Number(s):
- DOE/ET/27098-1
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
NATURAL GAS
PRODUCTION
BRINES
COMPUTERIZED SIMULATION
DATA COMPILATION
GEOPRESSURED SYSTEMS
GEOTHERMAL SYSTEMS
GRAPHS
MATHEMATICAL MODELS
NATURAL GAS WELLS
QUANTITY RATIO
RECOVERY
RESERVOIR ENGINEERING
TABLES
WATER
DATA
DATA FORMS
ENERGY SOURCES
ENGINEERING
FLUIDS
FOSSIL FUELS
FUEL GAS
FUELS
GAS FUELS
GASES
HYDROGEN COMPOUNDS
INFORMATION
NUMERICAL DATA
OXYGEN COMPOUNDS
SIMULATION
WELLS
Geothermal Legacy