ABSTRACT

Beds of Mesozoic age hold much promise of further oil and gas production in Central and Southern Mississippi without "getting farther downdip and drilling deeper". Examination of cuttings and cores from many wells in this area, and correlation with electrical logs of these wells, point out some areas which may contain favorable facies for oil and gas accumulation.

In Southwestern Mississippi, sediments from the Upper Tuscaloosa suggest a return to depositional environments prevalent in Lower Tuscaloosa time. The Lower Tuscaloosa is productive in this area from deltaic stream channel deposits. Some production is already established from the Upper Tuscaloosa.

Recent deep tests have added to knowledge of the Lower Cretaceous carbonate section in Southern Mississippi and this information can be used in interpreting the environment of deposition of the section. No porosity trends have been established but a few zones with some porosity are present.

In Central Mississippi, beds of Jurassic age can be reached at depths which are economically feasible to drill. The Cotton Valley is for the most part continental, but a few wells pierce beds which may be rich enough in organic material to be source beds. The Smackover Formation has possible objective zones in this area, but the belt of possible porosity is very narrow.

Stratigraphic cross sections in these favorable areas show the possible extent of favorable zones and help to explain the depositional history of these areas. Lack of identifiable fossils makes paleontological determinations very difficult. Lithologic studies with consideration of the environment and paleogeography are the most useful tools of study in this area.