--> Case Study: Evaluation of Hydrocarbon Potential, Southern Gas Region, United Kingdom North Sea, by Craig Davis; #91024 (1989)

Datapages, Inc.Print this page

Case Study: Evaluation of Hydrocarbon Potential, Southern Gas Region, United Kingdom North Sea

Craig Davis

The study area is in the southern gas region of the United Kingdom North Sea, on trend between the gas-producing fields of the United Kingdom sector and similar producing fields in the Dutch sector of the North Sea.

Structurally, the study area is on the western shelf of the Broad Fourteens basin and has undergone basin inversion in the Late Cretaceous. The primary reservoir targets are the Triassic Bunter Sandstone and the Permian Rotliegendes Sandstone, sourced by the Carboniferous (Mississippian) coal measures.

A number of wells have been drilled in the study area. The two most attractive drilling locations, a structural high in the northwestern portion of this two-dimensional seismic survey and a central high bounded by wrench faulting, did not contain commercial quantities of gas in the Bunter Sandstone. Generating an isochron of the shale formation capping the Bunter showed that in both cases the shale had been completely eroded at the highest structural position, removing the necessary seal.

The use of computer-aided exploration (CAEX) was critical in generating a thorough and accurate interpretation of this seismic survey. Had this technology been used prior to the drilling of wells, the Bunter Sandstone would have been recognized as having a very high risk.

The interpretation was performed on an interactive workstation, and is documented step-by-step through well integration, horizon and fault interpretation, mapping, and condusions.

AAPG Search and Discovery Article #91024©1989 AAPG Pacific Section, May 10-12, 1989, Palm Springs, California.