Petroleum Systems of the Campeche Area

L. D. Raedeke, R. C. Haack, J. E. Dahl, Noel Holguin-Quinones

In the greater Campeche-Sureste area four principal hydrocarbon systems and a fifth hypothetical system have been identified.

The Kimmeridgian-Tithonian-Berriasian hydrocarbon system comprises most of the oils in the area. The associated source rock section is composed of distinct carbonate-rich and shale-rich facies. The shaley Tithonian-Berriasian source is the richest and most widespread, generally improving toward the northwest.

The Oxfordian hydrocarbon system was identified in the vicinity of Ek-Balam by oil and rock samples from the Oxfordian shale-sand-evaporite section.

Oxfordian to Tertiary carbonate and clastic reservoirs, sealed by shales, tight carbonates and evaporites, provide a large number of viable plays for the two Upper Jurassic systems. The principal traps are compressional structures related to the Early Miocene Chiapaneco transpressional event, and/or related to Middle Miocene-Pleistocene salt diapirism. From Miocene to Present, the systems have been generating hydrocarbons, except in the northeast, where they are still immature.

The Lower Cretaceous Coban-equivalent hydrocarbon system, identified from oils in southern Mexico and northern Guatemala, has relatively low potential.

The Cenomanian-Turonian is a hypothetical system, identified by rock data only. Although it is locally oil-prone and rich, the unit is thin so generative potential is low.

The Tertiary (Miocene) hydrocarbon system was identified by a condensate from the Macuspana subbasin. The condensate's abundant oleanane and low maturity are consistent with a Miocene gas-prone source. Reservoirs and seals are Miocene sands and shales. Principal traps are related to salt diapirism. Generation began in the Pliocene and continues today.

AAPG Search and Discovery Article #91020©1995 AAPG Annual Convention, Houston, Texas, May 5-8, 1995