Structurally caused reservoir heterogeneity - its influence on reservoir performance

Conference · Thu Aug 01 04:00:00 EDT 1991 · Geobyte; (United States)

OSTI ID:5741523

Lewis, H ^[1]

---

1. Resource Consulting Group, Helensburgh (United Kingdom)

Geologic reservoir heterogeneity is the consequence of an original sedimentary framework and diagenetic and structural alterations to that framework. heterogeneity in the fluid system can also occur, due both to original reservoir charging characteristics and to production practices. This paper addresses the structural elements of reservoir heterogeneity - determination of structural reservoir partitioning distribution and its effect on porosity and permeability values. For any particular reservoir, the resulting structural model can be tested using reservoir performances. Anschutz Ranch East is a large asymmetric anticline in the thrust belt of Utah and Wyoming. The reservoir unit is the 300-m-thick aeolian Jurassic Nugget Sandstone. Reservoir operation is challenging, pressure maintenance having been required from the start of production. Sedimentology studies demonstrate stacked dune/interdune sequences, with the interdunes being sufficiently extensive to be significant barriers to vertical communication. Because of the combination of moderate initial porosity and the stress states and temperatures imposed during tectonism, the deformation mechanisms are typified by compactive modes, with accompanying reductions in porosity and permeability. Fortunately, structural methods allow prediction of deformation patterns, including division of the Nugget into several layer-bounded mechanical units, with layer-normal flow barriers within these units, and compartmental faults offsetting the fold crest. Use of modern structural concepts has allowed for improved prediction of pressures, fluid types, and connectivity of injectors and producers, and so an increase in efficiency of reservoir management.

• OSTI ID: 5741523
• Report Number(s): CONF-910978--
• Conference Information: Journal Name: Geobyte; (United States) Journal Volume: 75:8
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
ANTICLINES
DEVELOPED COUNTRIES
DIAGENESIS
ENGINEERING
FEDERAL REGION VIII
FRACTURED RESERVOIRS
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC STRUCTURES
JURASSIC PERIOD
MESOZOIC ERA
MINERAL RESOURCES
NORTH AMERICA
PERMEABILITY
PETROLEUM DEPOSITS
POROSITY
RESERVOIR ENGINEERING
RESERVOIR ROCK
RESOURCES
ROCKS
SANDSTONES
SEDIMENTARY ROCKS
USA
UTAH
WYOMING