Sabinas Basin Lower Cretaceous to Jurassic Production – Comparison to South Texas Equivalents

Michael J. Dyer and Claudio Bartolini
IHS Energy, Houston, Texas

This paper will attempt to draw some analogies to structural and stratigraphic similarities, and differences, between the productive Lower Cretaceous/Jurassic strata of the Sabinas Basin in Mexico with that of the San Marcos Arch area of South Texas where a wildcat drilled in 1969 logged interesting gas shows in a lower Hosston dolomite. The possibilities postulated for production in the South Texas strata will be based on these analogies. Jurassic to Lower Cretaceous stratigraphy has been correlated from the San Marcos Platform to the northern Burgos and Sabinas Basins of northern Mexico. The correlations and analogs between the two are important for exploration in South Texas. Lower Cretaceous to Jurassic strata of the Sabinas Basin include three important plays that produce from fractured formations, the La Virgen, La Casita, and the La Gloria. These have produced a combined 352 billion cubic feet of gas. Two important new discoveries are described.

Both Texas and Mexican data have been utilized, including well logs illustrating mutual stratigraphic relationships. A comparison of the productive structures of the Sabinas Basin to well logs and the seismic definition of a Jurassic wildcat drilled on the southeastern flank of the San Marcos Arch, suggests similar productive trends for the South Texas area may be possible. The Hosston dolomite lies on the Cotton Valley shale.

The shale is a proven source rock that is postulated to be within the gas generation window. Large down-to-the basin growth faults in the area created rollover anticlines, potential gas targets in fractured upper Sligo to Cotton Valley strata.

AAPG Search and Discovery Article #90032©2004 GCAGS 54th Annual Convention, San Antonio, Texas, October 10-12, 2004