East Cameron Block 270, Offshore Louisiana: A Pleistocene Field1
Exploration of the Plio-Pleistocene in the Gulf of Mexico since 1970 has led to the discovery of significant hydrocarbon reserves. One of the better gas fields found to date has been the East Cameron Block 270 field. Utilization of a coordinated exploitation plan with Schlumberger has allowed Pennzoil, as operator, to develop and put the Block 270 field on production in a minimum time.
The structure at Block 270 field is a north-south-trending, faulted nose at 6,000 ft (1,825 m). At the depth of the “G” sandstone (8,700 ft or 2,650 m), the structure is closed; it is elongated north-south and dips in all directions from the Block 270 area. Closure is the result of contemporaneous growth of the east-bounding regional fault.
Structural and stratigraphic interpretations from dipmeters were used to determine the most favorable offset locations. The producing zones consist of various combinations of barlike, channel-like, and distributary-front sandstones. The sediment source for most of the producing zones was southwest of the area, except for two zones which derived their sediments from the north through a system of channels paralleling the east-bounding fault.
Computed logs were used to convert conventional logging measurements into a more readily usable form for evaluation. The computed results were used for reserve calculations, reservoir-quality determinations, and confirmation of depositional environments as determined from other sources.
Figures & Tables
With three previous volumes published by AAPG on structure of American oil fields, this publication takes 17 of these oil fields and describes them in detail. The reservoirs described in these 17 papers range in age from Devonian to Pleistocene; their litholgies are standstone, limestone, or dolomite; and the trapping mechanisms are structural or stratigraphic or a combination of the two. The North American oil fields described are distributed from Alaska and the McKenzie Delta area of Canada on the northwest, to the Gulf of Mexico and Southern Floriday on the southeast. This publication also includes an index to those North American oil and gas fields which have been described in previous AAPG publications.