AAPG Bulletin, V. 84, No. 3 (March 2000), P. 299-313.

Scott L. Montgomery¹

©Copyright 2000. The American Association of Petroleum Geologists. All rights reserved.
¹Petroleum Consultant, 1511 18th Avenue East, Seattle, Washington 98112; e-mail: [email protected]
Grateful acknowledgment is given to MB Exploration (Dallas, Texas) for data and information included in this paper.

ABSTRACT

Newly released data from a 65 mi² (168 km²) 3-D (three-dimensional) seismic survey on the south flank of the Wiggins arch reopens the question of exploratory opportunity in this sparsely drilled region. Although surrounded by significant production from deep Jurassic and more shallow Cretaceous reservoirs, the Wiggins has not yet been the site of successful exploration. Only nine deep tests, however, exist within an area over 2000 mi² (5180 km²) in size; thus, previous interpretations of low potential on the Wiggins suffer from limited data. The recently completed 3-D survey, in conjunction with systematic evaluations of existing sample, well log, and 2-D (two-dimensional) seismic information, shifts the focus of attention from the Smackover Formation to overlying Haynesville and Cotton Valley intervals. Data suggest that large-scale oolite shoals exist in the upper Haynesville, immediately below the Bossier Shale. Potential shoals coincide in occurrence with a major northeast-southwest-trending anticlinal structure. Changes in the character of the Haynesville reflector imply significant porosity development, while time structure mapping and isochron thinning in the Haynesville-Cotton Valley interval indicate an important degree of potential entrapment in Cotton Valley sandstones. A well planned for an updip portion of the anticline should yield extremely valuable information for future analyses of Wiggins arch geology.