ABSTRACT

In 1972 regional computer-aided stratigraphic studies of 48 wells in a 185 sq mi area (479 sq km) resulted in the broad definition and ultimate drilling of the Mixon Creek prospect, leading to the discovery of Valentine field, Lavaca County. The Wilcox Group here is 4000 ft (1219 m) thick. Structural tops, interval sand counts, and isopachous data were measured in six deltas correlated on an electric log, jam correlation cross section network. Computer printouts showed the trends of successive delta fronts or barrier islands.

In Valentine field a northeast-striking barrier bar depositional model was used to pick essentially offset-development locations in producing lower Wilcox Technik sand. However, subsurface data from 11 oil completions and five dry holes exposed two shale-filled erosional channels, one dip-and one strike-oriented, which are partly responsible for the stratigraphic accumulation.

Menking field resulted from the accidental discovery of the oil in the Kubena sand, 100 ft (30.5 m) above the Technik sand, while drilling for the southwest projection of the Technik barrier across a tidal channel. Three oil wells and five dry holes there delineate a distributary channel sand truncated by erosion along the edge of a shale-filled channel.

Reserves in Valentine field are estimated at 975,000 barrels of oil and in Menking field at 310,000 barrels.