MAZZULLO, LOUIS J.
Ameristate Exploration, LLC, Albuquerque, NM and Midland, TX

Abstract: Geologic History and Reservoir Development in the Shoebar Field Area, Lea County, New Mexico

Production in the Shoebar Field area comes from many different types of reservoirs in rocks from the Siluro-Devonian up through and including the Permian Abo Formation. A complex structural setting in this area created a Paleozoic stratigraphy that is difficult to interpret with seismic data alone. The section from the upper Mississippian Chester through the upper Atoka Formations is further complicated by five major unconformities that can be related to differential movement and erosion along major faults. The timing of movement on these different faults and the magnitudes of their throws influenced deposition throughout the Pennsylvanian and Lower Permian, and restructured older rocks in the Siluro-Devonian.

Sample analyses and 2-D seismic data were used to unravel the depositional history of the Shoebar area, predict where reservoirs might be present in some underdeveloped sectors of the study area, and to aid in seismic interpretation. Particular attention was paid to distinguishing lithologies below each unconformity, and relating these to changes in thickness in the Mississippian, Morrow and Atoka sections. These data were used to predict depocenters for lower Morrow and Atoka sandstones, Strawn algal mound buildups, Cisco-Canyon detrital and algal mounds, and lower Wolfcamp algal mound and related facies. In addition, an attempt was made to explain lackluster production from Devonian wells that were drilled on structurally high areas. The result of this study is expected to broaden old plays and develop new plays in some of the same formations that have been producing in the area for years.

AAPG Search and Discovery Article #90918©1999 AAPG Southwest Section Meeting, Abilene, Texas