ABSTRACT

Pickens Field in Madison and Yazoo Counties, Mississippi was discovered by the Kingwood Oil Company No. 1 Wilburn in March, 1940. This well was drilled in eastern Yazoo County six months after the discovery of Tinsley Field in western Yazoo County. Pickens was the fourth oil and gas field discovered in Mississippi, and has produced 22,270,565 BBL of 38-40 gravity oil and 2,527,603 MCFG through the end of 1991 from seven Upper and Lower Cretaceous reservoirs. The Upper Cretaceous Eutaw Wilburn Sand has produced 20,387,303 BBLS (91.6%) of the oil and 2,157,485 MCFG (85.4%) of the gas. Second most significant reservoir is fractured Selma Chalk, which was discovered in March, 1963 and has produced 1,731,391 BBLS (7.8%) of oil and 329,860 MCFG (13.1%) from twenty-seven (27) vertical completions. These two reservoirs continued to be productive through the end of 1991.

Eutaw Wilburn Sand and fractured Selma Chalk oil production is only partially coincident. Eleven boreholes extending over a four mile distance west of the Eutaw producing area have produced seventy-seven per cent (77%) of the Selma oil. Four reservoirs in the Lower Cretaceous sequence have not produced significant volumes of reserves. An Upper Tuscaloosa reservoir discovered in 1989 remains to be more fully exploited.

A migrated CDP seismic line shot across Pickens Field and the Pickens graben fault system in 1982 displays a structural complexity not evident from subsurface mapping. Remaining productive potential may remain in Lower Cretaceous angular unconformity traps, fault blocks with four-way dip closure, selected untested upthrown fault closures in the Upper Cretaceous and fractured Selma Chalk in fault blocks adjacent to certain faults that may be associated with vertical migration.