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Title: Characterization of diagenetically altered carbonate reservoirs, South Cowden Grayburg Reservoir, West Texas

Conference ·
OSTI ID:471955
;  [1]
  1. Univ. of Texas, Austin, TX (United States)

Much of the difficulty in constructing carbonate reservoir models for fluid-flow simulation results from diagenetic overprinting of depositional permeability patterns. In the South Cowden field, diagenetic effects result in (1) low porosity and permeability in the western and northern areas due to reduction of porosity by means of dolomitization and post-dolomitization compaction, (2) elimination of the petrophysical effects of depositional texture resulting from changes in particle size due to dolomitization, and (3) creation of a touching-vug pore system due to anhydrite dissolution. The extent of anhydrite alteration can be mapped to show three distinct diagenetic areas: those dominated by unaltered, altered, or dissolved anhydrite. Each alteration type has a unique acoustic-porosity transform that can be used to map the diagenetic areas and to calculate porosity when only acoustic logs are available. A single porosity-permeability transform characterizes the areas having unaltered and altered anhydrite, and the depositional stratigraphy is useful in constructing a reservoir model. A more favorable transform characterizes the area of dissolved anhydrite, and depositional stratigraphy is not useful in constructing a reservoir model because of the large effect of the diagenetic overprint.

DOE Contract Number:
AC22-93BC14895
OSTI ID:
471955
Report Number(s):
CONF-961003-; TRN: 96:006579-0076
Resource Relation:
Conference: 71. annual technical conference and exhibition of the Society of Petroleum Engineers, Denver, CO (United States), 6-9 Oct 1996; Other Information: PBD: 1996; Related Information: Is Part Of 1996 SPE annual technical conference and exhibition: Formation evaluation and reservoir geology; PB: 960 p.
Country of Publication:
United States
Language:
English