Abstract

The Leonardian (Permian) Bone Spring Formation of the Delaware Basin consists of thick carbonate and siliciclastic (“sand”) members that were deposited in a slope and basin setting. Although three sand members have been defined previously, a fourth siliciclastic unit near the top of the formation has been identified recently in basinal areas. This fourth sand, the Avalon Sand, can be correlated to the Cutoff Formation of slope areas. This type of relationship is predicted by current sequence stratigraphic models. Application of sequence stratigraphic concepts has further potential in aiding exploration for, and development of, Bone Spring reservoirs.

Three-dimensional seismic technology, integrated with other computer-aided exploration tools, also has significant potential for helping exploration and development of the formation. The complete coverage afforded by a 3-D seismic survey allows for the evaluation of the controls on Bone Spring deposition. For example, Pennsylvanian structures can be shown to have influenced depositional processes and patterns of the Bone Spring sand members. Potential drilling targets, such as upslope depositional pinch-outs of the sand members, can be mapped by integrating seismic and log data. In basinal areas, productive intervals and the location and orientation of fracture swarms can be mappable using 3-D data. These conclusions are illustrated in this paper using examples from selected case studies.