CITRON, GARY P., Amoco Production Company, New Orleans, LA
ABSTRACT: Exploitation Impact of Second Generation 3D Surveys, Western Gulf of Mexico
Second generation 3D seismic surveys (2G3D) refer to those surveys re-acquired or re-processed over the same geographic area. In the western Gulf of Mexico, 2G3D's prove to be cost-effective exploitation investments, contribute heavily to better business decisions, and provide dramatic exploitation impact. Our sampling of six (6) surveys cover Plio-Pleistocene and Miocene age producing properties and environs. These 2G3D surveys are four to eleven years younger than their predecessors. Acquisition of the progenal surveys are distinguished from their predecessors by: (1) larger source array widths and volumes (typically a five times increase) with dual cable recording; (2) two to three times decrease in line spacing; (3) one to thirteen times increase in proprietary mileage collected; nd (4) a four to seven times increase in areal extent. The larger, denser 2G3D volumes have also benefitted from improved pre-stack (i.e. DMO) and post-stack(migration) processes in faster computers. Consequently, per mile costs have dropped by two to six times for acquisition, four to ten times for processing.
Comparison of new versus old horizontal and vertical slices illustrate the following exploitation impact: (1) while some amplitude targets disappear on 2G3D data, many others were not optimally penetrated by earlier drilling programs; (2) sharper focus of faults and stratigraphic variations better quantify and prioritize our prospect inventories; and (3) large (up to 100 bcf) resource bases have been quantified and more clearly interpreted in a regional framework.
AAPG Search and Discovery Article #90987©1993 AAPG Annual Convention, New Orleans, Louisiana, April 25-28, 1993.