More Effective
Use of Outcrops in Deep-water Studies
Nilsen, Tor H.1, Roger D. Shew2,
Gary S. Steffens3, Joseph R.J. Studlick4 (1) Deceased,
N/A, CA (2) University of North Carolina at Wilmington/Consulting Geologist,
Wilmington, NC (3) Shell International E & P Inc, Houston, TX (4) Maersk
Oil America Inc, Houston, TX
Whether a geoscientist is focused on the
basin, region, play, prospect, field, or reservoir scale in working with
deep-water deposits, selection of key analog data is critical. Outcrop data can
greatly assist in the construction of conceptual models using qualitative data
and in reservoir performance predictions using quantitative statistics. Outcrop
data provide the physical link between well-based data and seismic data.
However, as there are thousands of
published papers on the hundreds of deep-water outcrops, selecting the one(s)
applicable to your needs and extracting he right data
can be problematic. From a recent compilation of > 100 deepwater outcrops,
AAPG's Atlas of Deep-water Outcrops, we have summarized the data and developed
a simplified workflow to assist the worker in identifying the “best”
outcrop(s). We eliminated those outcrops that are inaccessible, difficult to
travel to, little studied, poorly exposed, and/or lacking a large 2-D or some
3-D perspective.
We characterized 75 outcrops by basin
setting, age, and depositional setting as key selection parameters. Additional
data available for each outcrop are stacking patterns, net:gross,
grain size, and references; most outcrops have detailed architectural element
data as channel dimensions, bed lengths, bed thicknesses, and textures of
reservoir and non-reservoir rocks. Using such criteria, one can quickly
identify the best outcrops to use. These data can then be used to establish
ranges and better estimates of sand thicknesses, connectivities, stacking
patterns, and recovery efficiencies. Use of photos from such outcrops and
preferably a visit to the outcrop by the work team can greatly assist the
understanding of and create a better “picture” of the deep-water deposits being
studied.
AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California