ABSTRACT: The Tuscaloosa Rejuvenated: Beaver Dam Creek and Baywood Fields, St. Helena Parish, Louisiana

Frank W. Harrison Jr., Gary E. Parrish

Recent discoveries in the Tuscaloosa Formation (Lower-Upper Cretaceous) of southeast Louisiana have opened a new trend that has the potential of yielding large reserves of hydrocarbons. Beaver Dam field in St. Helena Parish was discovered in early 1987 and has a proven oil reserve of 8 million bbl. Baywood field, also in St. Helena Parish, was discovered in September 1987, is being developed, and has a potential reserve of 50 bcf gas and 5 million bbl of condensate.

Beaver Dam and Baywood fields are located along a Tuscaloosa-age paleoshoreline, which strikes northwest-southeast across the Florida parishes of Louisiana.

The main producing sand, the Tuscaloosa "A" sand, occurs at 14,500 ft and does not require protective pipe to reach the objective. Seismic and subsurface data, the basic techniques used to locate features along the trend, suggest that many other potential traps are located along this interdeltaic depositional system and have hydrocarbon potential similar to Beaver Dam and Baywood fields. Using Beaver Dam and Baywood as an analog, it is almost certain that additional fields can be uncovered along the paleoshoreline.

Synthetic seismograms, models, and seismic logs are employed to augment the seismic stratigraphic interpretation. Sand pinch-outs on seismic lines are evident from an abrupt change in seismic character and prospective areas are associated with a pronounced flattening and/or a subtle arching along the paleoshoreline.

AAPG Search and Discovery Article #91003©1990 AAPG Annual Convention, San Francisco, California, June 3-6, 1990