ABSTRACT

The interpretation of seismic, gravity, and well data in northern Cameron Parish, Louisiana suggests that lateral salt flow has influenced the area's structural evolution, depositional patterns, and hydrocarbon migration. Sweet Lake field has produced over 46 MMBO and 15 BCFG from middle Miocene deltaic sands. The productive structural closure is a faulted downthrown anticline controlled by the underlying salt feature.

Sweet Lake field overlies a allochthonous salt mass that was probably once part of an ancestral salt ridge extending from Hackberry to Big Lake. Nine wells encountering top of salt and several seismic lines define a detached salt feature of more than 44 square kilometers (17 square miles) at depths from 8,560'-18,000'. Salt withdrawal in the East Hackberry-Big Lake area influenced the depositional patterns of the Oligocene lower Hackberry channel systems. Progradation of thick middle Oligocene Camerina (A) andMiogypsinoides sands into the area caused salt thinning and withdrawal, resulting in the development and orientation of the large Marginulina-Miogypsinoides growth fault northwest of Sweet Lake. Additional evidence for the southeast trend of the salt is a well, approximately 10 kilometers (6 miles) southeast of Sweet Lake, which encountered salt at approximately 19,800'.

High quality 2-D and 3-D seismic data will continue to enhance the regional understanding of the evolving salt structures in the onshore Gulf Coast and the local understanding of hydrocarbon migration. Additional examples of lateral salt flow in the onshore area will be recognized and some may prove to have subsalt hydrocarbon potential.