Maria Anunziata Romero1, Jose Ruiz1, Olfer Baltazar1, Luis Medrano1, Lenin Zea1, Federico Fernandez1, Ruben Dario Gomez1
(1) Pemex Exploracion y Produccion, Villahermosa, Tabasco, Mexico
ABSTRACT: Petroleum Systems of Mexico's Most Important Producing Region
The Pemex Northeast Marine Region is located in the Gulf of Mexico, offshore Campeche state. This Region has produced approximately 45% of Mexico´s crude oil over the last 20 years. Three source-reservoir petroleum systems have been identified in the area; Oxfordian-Oxfordian, Tithonian-Cretaceous, and Miocene-Pliocene. The first two are oil producers, whereas the third one is probably gas and condensate-prone but has not produced hydrocarbons yet. The two Mesozoic systems are well understood through the oil-source rock correlation, being the Tithonian-Cretaceous the most important with a contribution of over 90% of all crude oil produced up to the present by the Region. This is primarily due to the wide distribution and very high Source Potential Index (SPI) of source rocks in this system. In the Oxfordian-Oxfordian system, the SPI values are lower and source beds are less widespread. In the Miocene-Pliocene system, the source rocks are immature over a considerable part of the area. The greater production from the Cretaceous play is also a function of larger traps and greater reservoir thickness that have yet been found in Oxfordian and Pliocene accumulations. Migration and timing do not appear to be major factors in the great variation in reserves of these three systems.
AAPG Search and Discovery Article #90906©2001 AAPG Annual Convention, Denver, Colorado