Geothermal reservoir evaluation considering fluid adsorption and composition

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1984

OSTI ID:6029922

Economides, M J

Previous reservoir engineering studies of vapor-dominated geothermal reservoirs have generally been analogous to conventional-model studies of natural gas reservoirs. One inconsistency in past work has been the discrepancy between the estimated quantity of steam-in-place and the geological constraints of the estimated reservoir bulk volume. The concept that considerable adsorbed water may exist in a vapor-dominated zone is examined in detail here. Experimental and theoretical evidence of adsorption phenomena is described. Then, the implications of adsorption on material balance calculations and on well test analysis are determined by incorporating adsorption effects into existing models. The resulting new methods of analysis provide a more realistic estimate of the nature and extent of the vapor-dominated zone. In particular, the new methods result in a considerable reduction in the estimated formation thickness and suggest that the fracture porosity has been underestimated using conventional models for a naturally fractured reservoir. This work shows that a reserve estimate based on geologic evidence and the thermodynamic properties of steam could be as much as an order of magnitude lower than the actual mass of water present.

• OSTI ID: 6029922
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
150100 -- Geothermal Energy-- Resources & Availability
150902* -- Geothermal Engineering-- Fluid Transmission
ADSORPTION
ENGINEERING
EXPLORATION
FLUID FLOW
GEOTHERMAL EXPLORATION
GEOTHERMAL RESOURCES
NUMERICAL SOLUTION
RESERVES
RESERVOIR ENGINEERING
RESOURCE ASSESSMENT
RESOURCES
SORPTION
STEAM