Application of Highly Inclined Wellbores in a Stratified Reservoir, San Andres Formation, Hockley County, Texas

Stephen N. Guillot

A CO₂ injection project was initiated by Texaco in the Slaughter field on the northern edge of the Permian Basin in January 1994. Horizontal boreholes were seen as an opportunity to increase through-put and have a potentially dramatic impact on the economics of this project, particularly when employed as CO₂ injectors. A truly horizontal well would probably not be effective in flooding this stratified reservoir, so highly deviated, or inclined wells were drilled that would expose all layers to be flooded. In addition, it was predicted that these wells would enhance the existing line-drive injection pattern and effect an improvement in areal sweep efficiency.

This poster session includes a geological description of the Slaughter field which will illustrate its stratified nature. It presents the reasoning for incorporation of inclined wells in the development plan for the field. It also includes details on how the wells were completed in the target zone and plans for monitoring performance. A determination of the expected improvement in injection rate using adaptations of several published methods is also presented.

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