Petroleum Systems of the Campeche Area

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

Two Upper Jurassic hydrocarbon systems were identified. The Kimmeridgian-Tithonian-Berriasian system comprises most of the oils in the greater Campeche-Sureste area. Within the section, the shaley Tithonian-Berriasian source is the richest and most widespread, generally becoming richer toward the northwest. The Oxfordian system was identified in the vicinity of Ek-Balam.

Oxfordian to Tertiary carbonate and elastic 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, whose 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