Geologic factors affecting reservoir analysis, Anschutz Ranch East Field, Utah-Wyoming

Conference · Wed Sep 01 04:00:00 EDT 1982 · Soc. Pet. Eng. AIME, Pap.; (United States)

OSTI ID:5467998

Lelek, J J

The Anschutz Ranch East field, a retrograde condensate accumulation discovered in late 1979, is the giant of the exciting western U.S. Overthrust Belt. As continuous drilling provides new data, evolving geologic interpretations necessitate changes in production and reserve estimates. The interpreted areal extent of the field has changed many times since the initial prospect map was prepared. The current interpretation has separate reservoirs in two tightly folded, overturned, en echelon, anticlines. Production is from the eolian Jurassic Nugget sandstone, which averages 1,050 feet in thickness. Cross-bedded units formed by dune migration constitute the better reservoir rock and may cause field-wide permeability anisotropy. Interbedded with these units are interdune deposits of poorer reservoir quality. On the basis of depositional theory (to be tested by analysis of core, log, and production data), complex fluid flow within the reservoir may be expected, and reservoir modeling efforts will consider this expectation. Diagenetic events and the effects of structural deformation (reservoir attitude, fractures) will also affect reservoir flow. In the area of steeply dipping beds, it is difficult to determine hydrocarbon pore volume. Towards this end, detailed geologic mapping and correlation becomes crucial. Reservoir analysis must be synergistic with geologic input to accommodate a constantly evolving geologic interpretation.

• Research Organization: Amoco Production Co.
• OSTI ID: 5467998
• Report Number(s): CONF-820927-
• Conference Information: Journal Name: Soc. Pet. Eng. AIME, Pap.; (United States) Journal Volume: SPE 10992
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
03 NATURAL GAS
030200 -- Natural Gas-- Reserves
Geology
& Exploration
ANISOTROPY
ANTICLINES
DIAGENESIS
DRILLING
ENGINEERING
EXPLORATION
FEDERAL REGION VIII
FLUID FLOW
FLUIDS
GAS CONDENSATE FIELDS
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC STRUCTURES
JURASSIC PERIOD
MAPPING
MATHEMATICAL MODELS
MESOZOIC ERA
MINERAL RESOURCES
NATURAL GAS DEPOSITS
NORTH AMERICA
PERMEABILITY
PETROLEUM DEPOSITS
RESERVOIR ENGINEERING
RESERVOIR FLUIDS
RESERVOIR ROCK
RESOURCE POTENTIAL
RESOURCES
ROCK-FLUID INTERACTIONS
USA
UTAH
WELL DRILLING
WYOMING