Possible Future Petroleum Provinces of United States Western Gulf Basin--Eocene and Paleocene: ABSTRACT

Abstract

Two new important future petroleum provinces, gas in Texas and oil in Louisiana, are related to the Wilcox Group. The gas province in Texas covers 8,700 sq mi and has 12,000 cu mi of untested sedimentary rock. In Louisiana, the oil province covers 5,800 sq mi and contains, 3,800 cu mi of untested sedimentary rock. Another possible future oil province, which covers 8,000 sq mi in Texas and Louisiana and has 7,000 cu mi of untested sedimentary rock, is predicted for the Claiborne Group. No new province is foreseen for the Jackson and Midway Groups. New provinces for the Wilcox and Claiborne Groups more appropriately might be described as gulfward extensions of existing producing trends. This report, concerned with possible future Paleocene-Eocene provinces of the western Gu f basin, assumes that technologic advances will permit drilling and production of wells to depths of 30,000 ft. Considerable quantities of both oil and gas have been found in the established Eocene trends. Currently, there are 501 gas, 1,048 oil, and 377 oil and gas fields which have produced from Eocene deposits. Cumulative production to January 1, 1969, totals in excess of 4.2 Tcf of gas and 2.8 billion bbl of oil. These figures do not include casinghead gas, natural gas liquids, and gas flared in past years. Large structures are known to be present at shallower depths within the future prospective areas. Structurally, these areas will be similar to the established trends; regional growth faults will predominate. Faultline and salt-related structural traps will be prevalent. To reduce economic risk, it will be important to use all available subsurface information for detection and definition of depositional trends which may project into the provinces. The greatest attraction in the provinces will be from the Wilcox sandstone. Claiborne exploration will be a by-product of the Wilcox wells. It is not expected that the industry will rush into the provinces, but deep exploration will move gradually farther gulfward as more knowledge is accumulated. Three present fields have provided, and will continue to provide, encouragement for gradual movement into the future areas. In Texas, Northeast Thompsonville and North Milton fields, with reserves estimated at 500 Bcf to 1 Tcf of gas, are along the landward edge of the predicted Wilcox gas province. Fordoche field, with Wilcox oil reserves estimated at 70-120 million bbl, also lies on the landward edge of End_Page 1786------------------------------ the predicted oil province in Louisiana. These 3 fields provide significant clues to productive possibilities within the future provinces. End_of_Article - Last_Page 1787------------