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Title: US Gulf Coast geopressured-geothermal reservoir simulation. Final report (Year 3)

Technical Report ·
DOI:https://doi.org/10.2172/6548221· OSTI ID:6548221

Several reservoir model improvements incorporated into the UTA model are described. The most significant modification to the model was the inclusion of semiimplicit treatment of transmissibilities so as to better handle two-phase flow problems associated with flow near the wellbore. A description of the reservoir mechanics presumed operative in geopressured-geothermal reservoirs is included. A mathematical model describing two-dimensional flow in compacting porous media is developed from the Lagrangian point of view. A description of the way the differential equations are approximated by finite differences and subsequently solved by means of numerical procedures is presented. Various sensitivity studies made with the reservoir model are described. Particular emphasis was given to the study of potential shale dewatering effects on reservoir depletion and the effects of compaction on fluid recovery. To study shale dewatering, the shale thickness and the shale vertical permeability were treated as variables in several simulation experiments. The effects of compaction were modeled with optimistic and pessimistic values for the uniaxial compaction coefficient in an attempt to define a region of expected reservoir performance. Laboratory analysis of core samples obtained from the geopressured-geothermal test well was completed by the end of year 3. These data indicate that the uniaxial compaction coefficient is of the same order of magnitude as the pessimistic value used on the sensitivity studies. Because of this the expected fluid recovery from geopressured reservoirs has been reduced to a nominal 5% of the in-place volumes rather than the previously reported 10%.

Research Organization:
Texas Univ., Austin (US). Center for Energy Studies (US)
Sponsoring Organization:
Not Available (US)
DOE Contract Number:
AC05-76ET28463
OSTI ID:
6548221
Report Number(s):
DOE/ET/28463-T1; ON: DE83005131; TRN: US200508%%61
Resource Relation:
Other Information: Portions are illegible in microfiche products; PBD: 1 Jan 1979
Country of Publication:
United States
Language:
English