Abstract: Pressure Architecture of the Anadarko Basin: Implications For Exploration and Production

PUCKETTE, JIM, and ZUHAIR AL-SHAIEB

The evaluation of pressure data from the Anadarko basin indicates that the rook column is divided into three major pressure domains: 1) shallow normally pressured interval, 2) overpressured mega-compartment complex (MCC), and 3) deep normally pressured zone. This tiered pressure system demonstrates that there is no hydraulic continuity between them.

The overpressured interval is typically encountered in the upper Desmoinesian (around 8,000 to 10,000 ft) and extends to the Mississippian-Devonian Woodford Shale. The overpressured basin-scale compartment (MCC) is dominated by siliciclastic rocks with the textural variability and mineralogic diversity conducive to seal formation. Normally pressured reservoirs below the Woodford Shale are predominantly carbonates and sandstones in the Hunton, Simpson and Arbuckle Groups. These rocks have great lateral continuity and remain normally pressured over most of the basin. Therefore, abnormal pore pressure generated by various processes was not maintained as a result of the hydraulic continuity between outcrops and the subsurface reservoirs.

The basin-scale overpressured domain is highly compartmentalized. Most gas accumulations are independent of structural position and often require particular facies to be productive. Other compartments contain separate gas and brine columns or brine only. Normally pressured reservoirs below the basin-scale compartment have active water drives and gas accumulations occur primarily in anticlinal traps.

The productive potential for the MCC is high across the basin. However, it decreases in the vicinity of the Wichita fault zone. On the other hand, the deep normally pressured rocks remain viable exploration targets up to and within the fault zone.

AAPG Search and Discovery Article #90944©1997 AAPG Mid-Continent Section Meeting, Oklahoma City, Oklahoma