Facies
Architecture and Reservoir Prediction in Ancient Glaciogenic Sediments: a Case
Study using Integrated Outcrop and Subsurface Studies of the Grant Group (
Martin, Joe R.1, Jonathan
Redfern1, Brian P. J. Williams2 (1)
The recognition of ancient glaciogenic
facies suites from subsurface data is prone to difficulty. Most
sedimentological criteria used to define a glacial origin relies
on large scale geomorphic features that cannot be distinguished either in core
or on wireline logs. Glaciogenic facies suites are often complex and
understanding the mode of deposition is crucial to generation of reliable
reservoir models.
This study details results of an
integrated study of late Carboniferous to early Permian glaciogenic deposits in
the
Fully cored stratigraphic boreholes from
the Barbwire Terrace, along the flanks of the Fitzroy Trough, provide an
extensive subsurface datasets of the same interval. Sedimentary lithofacies in
outcrop comprise glacially-influenced shallow water deposits, many within a
deltaic setting. Evidence for glacial influence comes from striated units,
dropstones and diamictites. Many of the glacial features recorded in outcrop,
however, could not be observed in core, although similar facies associations
can be observed. The use of outcrop gamma-ray provided invaluable information
on subtle variations in grain-size and cyclicity and facilitated
lithostratigraphic correlation with the subsurface.
AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California