Our recent multidisciplinary study resulted in a better biostratigraphic, sedimentologic, tectonic-structural, and geochemical understanding of the Tertiary section in Reforma-Comalcalco area as a part of the Sureste Basin of Mexico. Our objectives were to identify, define, and delimit the proven and potential plays.

During the Paleocene to middle Miocene, deep-water organic-rich shales were deposited, whereas debris flows and breccias were deposited on a slope derived from exhumed Cretaceous platforms. These sedimentary facies resulted from a compressive Laramide phase, which generated a broad regional fold belt. The Miocene–Pliocene Chiapaneca orogenic phase redeformed the former structures generating large volumes of terrigenous detritus and consequent rapid progradation of the clastic shelf facies. The paleoenvironments became aggradational-deltaic in nature from the early Pliocene onward; major gravity sliding processes triggered the separation of the Comalcalco and Macuspana subbasins.

Rapid burial during the Tertiary favored hydrocarbon generation and expulsion from the Tithonian source rock. The main generation phase occurred in the late Oligocene. The vertical migration of hydrocarbons along normal faults occurred in the Pliocene–Pleistocene charging the Neogene traps. Diagenetic processes of compaction, cementation, dissolution, and fracturing modified the sandstone porosity and permeability, thus influencing hydrocarbon migration and accumulation in the reservoirs.

Through our integrated analysis, we have identified nine play fairway complexes with hydrocarbon reserves and future economic potential. Each of them could have multiple and important individual plays.