ABSTRACT

Interpretation of recent seismic and well data in the Gillis-English Bayou and West Manchester area of Calcasieu Parish, Louisiana, supports a complex structural history involving allochthonous salt, erosion and faulting. Since its discovery in 1934, Gillis-English Bayou has produced over 195 BCFG and 18 NMBL from Oligocene and Miocene age sands. Unlike the aerially small, shallow salt dome fields along trend, Gillis-English Bayou covers approximately eighteen square miles, by area the largest field in the parish. West Manchester, to the south, has produced over 120 BCFG and 2 MMBL from Oligocene Lower Hackberry sands. The associated salt sill underlies at least thirty square miles at depths of 15,000 to 20,000 and can be indirectly related to hydrocarbon accumulation in the area. Associated with this vertical and lateral movement of salt is a significant Vicksburg erosional event underlying West Manchester Field. In this area of thick Vicksburg sediments, over 1,200 of section is absent.