Print this pageSlope to Basin Transition: Bone Spring Formation Reservoirs, Delaware Basin, New Mexico
HART, BRUCE S.
The Leonardian (Permian) Bone Spring Formation of New Mexico records a well-defined transition from slope to basin floor deposits. These rocks were primarily deposited by slope and deep water resedimentation of carbonate and clastic detritus supplied from carbonate-dominated platforms around the periphery of the Delaware Basin. The formation is divided into thick, carbonate and clastic ("sand") members that reflect the history of relative sea level change within the basin. Current sequence stratigraphic models suggest that the siliciclastic sediments were delivered to the basin during relative sea level lowstands. Using 3-D seismic and well data it is possible to identify stratigraphic features such as density current channels and debris lobes, and so help establish sediment dispersal processes that affect the distribution of reservoir quality rock. Reservoirs in the Bone Spring are the product of complex interactions between depositional processes, diagenesis and structural deformation. Production, including oil and gas from both carbonate and sand members, is mostly from a "fairway" within 5-15 miles of the shelf edge. Dolomitized debris mounds are common drilling targets on the slope. Other fields are currently being discovered and produced in basinal areas further south where reservoirs are associated with certain combinations of stratigraphic (e.g., channels), diagenetic and structural elements. Various completion strategies, typically involving acidization and artificial fracturing, have been attempted in these stratigraphically and lithologically complex units. Good analogies exist between the Bone Spring and other Deep Water Sands of the Permian Basin (e.g., Spraberry, Delaware Mountain Group).