Exploration in Jurassic of North Mafla, Eastern Gulf of Mexico
David A. Kemmer
Exploration in North Mafla focuses on general categories of prospects, potential reservoirs and their associated facies, and seismic modeling of available well control.
Jurassic prospects in North Mafla can be classified into four general categories: (1) basement-related structures, (2) closures associated with the Pensacola-Destin peripheral fault trend, (3) salt anticlines, and (4) prospects associated with the interregional structural highs. Each of these categories can be related to documented, predictable, and repeated patterns of hydrocarbon accumulations in east Texas, north Louisiana, Mississippi, Alabama, and Florida.
The primary objectives in North Mafla are the Jurassic Smackover carbonates and Norphlet sands at depths ranging from 15,000 to 25,000 ft. Major gas accumulations in the Norphlet around Mobile Bay are separated from thicker sequences of Norphlet sands in the De Soto Salt basin by the offshore extension of the Pensacola arch. Seismic geometries suggest that Smackover high-energy carbonates may have been deposited on the crest of some of these thick Norphlet sands.
Seismic modeling indicates that a high-amplitude, laterally continuous event associated with a Norphlet-Louann Salt contact is dependent on the presence of Pine Hill anhydrite member of the Louann Salt. In addition, seismic reflection geometries indicate that the Norphlet sandstone thickens from ± 300 ft on the eastern flank of the Destin Dome to nearly 1,000 ft nearby.
Although drilling in the lightly explored North Mafla area has yielded few substantive results to date, the elements necessary for significant hydrocarbon accumulations are known to exist.
AAPG Search and Discovery Article #91038©1987 AAPG Annual Convention, Los Angeles, California, June 7-10, 1987.