Upper Miocene and Pliocene Shallow-Marine and Deep-Water, Gas-Producing Systems in the Macuspana Basin, Southeastern Mexico

By

AMBROSE, WILLIAM A., JONES, REBECCA, WAWRZYNIEC, TIM, FOUAD, KHALED, DUTTON, SHIRLEY P., JENNETTE, DAVID C., ELSHAYEB, TAREK, SANCHEZ-BARREDA, LUIS

Bureau of Economic Geology, John A. and Katherine G. Jackson School of Geosciences, The University of Texas at Austin, Austin, TX,

SOLIS, HECTOR, MENESES-ROCHA, JAVIER, LUGO, JORGE, AGUILERA, LEONARDO, BERLANGA, JOSE, MIRANDA, LINO, RUIZ MORALES, JOSE, and ROJAS, ROBERTO

PEMEX Exploración y Producción, Macuspana, Villahermosa, and Ciudad del Carmen, México

The Bureau of Economic Geology and PEMEX Exploración y Producción conducted a joint study of gas plays in the Macuspana Basin, which shows that most gas production currently occurs in upper Miocene and Pliocene shallow-marine shoreface and wave-dominated deltaic systems in the onshore part of the basin. However, additional potential also exists in upper Miocene deep-water systems in the less-developed offshore part of the basin.

The upper Miocene shoreface and wave-dominated deltaic complexes in the onshore part of the basin were sourced from north- and northwest-trending fluvial systems from the Chiapas foldbelt. Episodic movement along growth faults in the east and southeast parts of the basin intermittently halted progradation, controlling sandy deltaic depocenters. Traps occur as both four-way and three-way structural-stratigraphic combinations. Reservoir seal is provided by a 200- to 400-m lower Pliocene transgressive shale. Downdip pinch-out of reservoir-quality shoreface sandstones is a key risk factor in the onshore part of the basin.

The offshore upper Miocene consists of deep-water slope systems downdip of an inferred mixed clastic-carbonate source associated with the Yucatan Platform. Thin calcareous turbidite sandstones lapped onto a major turtle structure, potentially providing updip-porosity pinch-outs in offshore stratigraphic traps.

The Pliocene contains multiple sandy shoreface depocenters in shale-withdrawal subbasins, primarily in the northwest part of the basin. The upper Miocene was also affected by shale withdrawal to a lesser extent. Unlike the more productive upper Miocene, reservoir seal is a major risk factor in upper and middle Pliocene reservoirs lacking thick upper bounding shales.