Print this pageRevitalization of an Old Play--Shallow, Piercement Salt Domes in the Mississippi Interior Salt Basin
ERICKSEN, RICK L
There are 53 documented, piercement salt features in Mississippi whose crests are shallower than 6,000 feet. During recent exploration, non-proprietary, 2-D seismic data and subsurface control have been supplemented by additional, high quality, 2-D seismic lines.
Trapping occurs when strata are pushed upward by movement of the salt diapir. The caprock/salt face of the diapir is juxtaposed against potential reservoir beds prior to or penecontemporaneously with hydrocarbon migration. Previous exploration led to the erroneous conclusion that all diapiric salt movement was late (Tertiary), after the generation and migration of hydrocarbons. As a result little exploration activity ensued. This concept has been challenged and it appears at least for some domes there were' periods or pulses of growth/salt movement during the Cretaceous. An example of pulsed salt movement is evidenced at Dry Creek Dome Field, which exhibits an angular unconformity in the Hosston. Carson Dome Field, located in Jefferson Davis County, was the discovery associated with a salt diapir which set off the current flurry of drilling. Drilling activity around piercement domes has surged as a result of this shift in thinking, with most of the current exploration activity being conducted by Amerada Hess and Fina.
There are two problems inherent to this play which are the result of salt movement: (1) seismic imaging difficulties because of high angle dips of surrounding strata at depth; and (2) reservoir compartmentalization due to faulting and fracturing. Both of these factors, particularly the latter, must be reckoned with as this play matures.