Interaction of Salt Tectonics, Slumping and Channeling: Mid-Pliocene Reservoir System, Pompano Field, Gulf of Mexico

C. L. Blankenship, D. A. Stauber, D. S. Epps, C. G. Guderjahn, and J. D. Oldroyd

Newly reprocessed 3-D seismic, converted to Acoustic Impedance, shows the detailed stratigraphy of the mid-Pliocene, upper slope reservoir system of the Pompano Field. This improved data allows us to view the internal slumping and channeling in an interval which was previously poorly imaged. Pompano is located in the Gulf of Mexico at the boundary of Mississippi Canyon and Viosca Knoll.

Overall structure of the field is governed by a salt diapir in the footwall of a counter-regional growth fault. Stratigraphy is dominated by slumping and channeling. Slumping was initiated by salt evacuation and diapir formation. South of the diapir slumps appear to be directed basinward, and are confined to a zone approximately 3 miles wide, oriented NNW-SSE. Topographic lows formed by slumping are interpreted to have focused early channels, which are typically amalgamated, and usually less than 1/2 mile wide. As the system evolved, channelized sediment filled the slump zone, and then spread outside of it. These younger channels are roughly the same size as the older channels, but tend to be more isolated and constructional.

Hydrocarbons are trapped in the sandy channel fills of the slump/channel complex where it is structurally high adjacent to the salt diapir. Reservoir quality is good, but the combination of channeling and faulting make reservoir management challenging. Detailed mapping of the reservoir, geologic models of the slump/channel complex (aquifer) and production data form the basis of a reservoir simulation model run to investigate options for field management.

AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California