Structural Styles of the Campeche Shelf Reservoir Rocks

Antonio Murillo¹, Jaime Rios¹, Gerardo Figueroa¹, Roy Lindseth², Daniel Hsu², Vladimir Popovic², and Tom Jerzykiewicz^2
1 Pemex PEP Region Marina Norests, Cd. del Carmen, Campeche, Mexico
² Teknica Mexicana, S.A. de C.V, Cd. del Carmen, Campeche, Mexico

Several stages of tectonic activity related to the plate movement have been documented with two of them closely related to the present-day structure configurations of producing reservoirs in the Campeche shelf of southern Gulf of Mexico. Late Triassic and Jurassic rifting and Neogene compressional stresses accompanied by strike-slip faulting causing folding and thrusting are evident. Intensity and style of tectonic deformation change across the basin. Several factors contributed in various degrees to a rather complex, multiphase and eclectic structural style of the Campeche basin-fill. Salt mobilization due to differential sediment loading and compaction, instability in density stratification facilitated folding, thrusting and gravitational sliding. Impact of these factors on any particular reservoir needs to be considered case-by-case. For example, the Cantarell, Ku-Maloob-Zaap and Sihil reservoirs have been interpreted as en echelon thrusted anticlines within the PDZ of a major strike-slip system. A different case can be made for anticlinal traps related to salt tectonics as a force of initial folding. Many forms of salt structures are readily observable on seismic sections, most notably, salt pillows, salt diapirs, salt walls and salt canopies. Tectonic forces and sediment loading caused salt to rise and/or to withdraw at different times. This gave rise to extremely complex structures and fault patterns within the surrounding sediments. We concluded that the structural style of the Campeche basin-fill is site-specific and should not be generalized but rather carfully assessed in order to minimize the exploration and exploitation risk.

AAPG Search and Discovery Article #90039©2005 AAPG Calgary, Alberta, June 16-19, 2005