From Slope to Basin – An Unconventional Online Core Series Focusing on the Variety of Gravity Flow Deposits throughout the Permian Basin
American Association of Petroleum Geologists
Monday, 20 July – Wednesday, 22 July 2020, 7:00 a.m.–7:00 p.m. | Austin, Texas
Xavier Janson, Jake Covault, David Carr, Buddy Price, Ali Sloan, Zoltan Sylvester; and Charles Kerans
AAPG and Devon have partnered with research groups of the UT-Austin Bureau of Economic Geology to provide an online Permian Basin core series to attendees. Videos of the core series will air during the live URTeC program and will be available on demand until December 31, 2020.
Whole core from both the Delaware and Midland basins will be examined to understand the changes in slope deposits from confined to unconfined settings. We will examine a variety of gravity flow deposits within the basins and the processes from which they were deposited. The ultimate goal of this series is to understand how these deposits impact reservoir quality in the basins.
The selection of cores from the Delaware Basin will contrast rock deposits in confined slope, unconfined toe-of-slope, and basin-floor environments. We will examine several cores that provide examples of both carbonate and siliciclastic deposits of the Wolfcamp A (Leonardian), 2nd and 3rd Bone Spring, and Avalon plays. We interpret depositional elements including channelized debris-flow deposits, grainy confined slope fans, and unconfined basin-floor fan off-axis to fringe deposits. When placed within a larger depositional framework, these cores provide an anchor point for explaining the proximal to distal facies transition within the Delaware Basin’s Permian mixed-system.
Cores in the Midland Basin will focus on the Spraberry Formation. These cores will show three main facies types: turbidites, hybrid-event beds (HEBs), and a parallel laminated siltstone facies. The main point of discussion will center around the origin of the enigmatic laminated facies and its relation to the turbidites and HEBs. Preliminary observations suggest that some laminated intervals can be correlated across a distance of >1.3 km, with a high certainty, at a lamina-by-lamina scale. This is consistent with the idea of settling of fine-grained sediment from density currents that are not hugging the bottom but spread out along a pycnocline or suspension fall-out of aeolian dust. The fine-scale correlatability of the laminated facies also suggests the potential for robust long-distance correlations in similar settings.
Cores from both the Midland and Delaware basins can be applied as analogs for strata of different ages and in other deep-water basins with similarly interpreted depositional environments.
We are grateful for logistical assistance from UT-Austin BEG Core Research Center Manager Nate Ivicic and his team.
Austin, TX - Bureau of Economic Geology
10611 Exploration Way