Characterization of heterogeneity style and permeability structure in fluvial-deltaic reservoirs deposited in a low-accommodation setting

Journal Article · Tue Aug 01 04:00:00 EDT 1995 · AAPG Bulletin

OSTI ID:127395

Dutton, S P; Gardner, M H; Willis, B J ^[1]

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1. Univ. of Texas, Austin, TX (United States)

Because of the worldwide importance of resources in fluvial-deltaic reservoirs, a consortium of companies is funding research at The University of Texas aimed at reservoir characterization of fluvial-deltaic depositional systems. The goals of this industrial associates program are to develop an understanding of sandstone architecture and permeability structure in a spectrum of fluvial-deltaic reservoirs and to translate this understanding into more realistic, geologically constrained reservoir models. Our approach is to quantify the interrelationships among sequence stratigraphy, depositional architecture, diagenesis, and permeability structure through detailed outcrop characterization. The current project focus is the Lower Cretaceous Fall River Formation, a deltaic system deposited in a low-accommodation setting in South Dakota and Wyoming, USA. The Fall River is exposed around the margins of the Black Hills Uplift and produces oil and gas in the adjacent Powder River Basin. Extensive field work established the Fall River as a storm- and tide-dominated deltaic depositional system in which the shallow-water marine deposits were locally removed by valley incision during periods of base-level fall. Valley-fill sandstones, which form the most productive Fall River reservoirs, were deposited during base-level rise and grade upward from low-sinuosity fluvial to estuarine deposits. Permeability structure in marine and valley-fill deposits was determined from >5,000 minipermearneter data points in vertical and horizontal transects. In this low - accommodation setting, unconformity-bounded valley fills are flow units, and pronounced lateral changes in permeability occur where valley fills of different character am juxtaposed. The interpretations of the Fall River that were developed on outcrop air being used to guide characterization of Buck Draw field, a Fall River field with an outstanding suite of cores and reservoir production data.

• OSTI ID: 127395
• Report Number(s): CONF-950995--
• Journal Information: AAPG Bulletin, Journal Name: AAPG Bulletin Journal Issue: 8 Vol. 79; ISSN 0149-1423; ISSN AABUD2
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
58 GEOSCIENCES
DIAGENESIS
EDUCATIONAL FACILITIES
GEOMETRY
MAPPING
PERMEABILITY
RESEARCH PROGRAMS
RESERVOIR ROCK
SANDSTONES
STRATIGRAPHY