Controls on the Distribution of Oil and Gas, Mesozoic and Cenozoic of Mississippi

Through 1995, oil and gas had been produced from 871 fields in Mississippi, cumulative production being 2,168 Mbbl (million barrels) of oil and 8,835 Gcf (billion cubic feet) of gas. About 6 per cent of the gas, but only 0.1 per cent of the oil, came from the 69 Paleozoic fields in the Black Warrior Basin of northeastern Mississippi. The other 802 fields are in central and southern Mississippi, and produced from Norphlet (Upper Jurassic) up through Frio (Oligocene) reservoirs. Of these 802 fields, 322 have produced at least 0.5 Mbbl oil and/or 3 Gcf gas from a single stratigraphic unit. The areal and stratigraphic distribution of hydrocarbons from these 322 fields reveal the principal controls on production. Most of the oil and gas is located in two general settings: (1) structural traps updip from the Perry Basin, a pronounced low in the eastern Mississippi Salt Basin, or (2) combination stratigraphic-structural traps on the Adams County High of southwestern Mississippi. Hydrocarbons from Smackover and possibly younger source rocks in the Perry Basin may have migrated updip along graben faulting related to salt ridges that extend into the basin. North of the Perry Basin, production is mainly Smackover, Cotton Valley, Sligo, Rodessa, and Eutaw oil. West and northwest of the Perry Basin, on a structural terrace that separates it from the Mississippi Embayment part of the salt basin, and at depths greater than on the north side of the Perry Basin, pay is mainly gas from the Hosston, Sligo, Rodessa, and Paluxy. Hydrocarbons on the Adams County High (and some of the pay in structures within the southern part of the salt basin) likely migrated updip from source rocks in Louisiana. This production is mainly Lower Tuscaloosa oil and gas and Wilcox oil. The massive Jackson Dome of west-central Mississippi, a Late Cretaceous igneous intrusion, occurs in an area with very limited oil production (other than Tinsley field). This likely reflects the thermal impact of the intrusion, which has produced carbon dioxide and sour gas in Upper Jurassic units in fields north, east, and south of the structure