KHAN, M. ALI, Division of Oil & Gas, Department of Conservation, Santa Rosa, CA

ABSTRACT: Arkla-Mafla Fields Study: A Key to Exploration Strategies

Discovery pattern and size of fields in Arkansas, Louisiana, Mississippi, Alabama and Florida producing from Norphlet, Smackover, Buckner and Haynesville formations have been analyzed. The aim was (1) to assimilate publicly available reservoir parameters; (2) to calculate EUR, field life and other factors that will affect the NPV; (3) to reduce the calculated numeric data into simple models for formulating exploration strategies. There are 325 fields in this 400 miles long and 250 miles wide play. The ultimate recoverable reserves are 1,600 MMBO and 9,000 BCFG.

These fields are divided into nine groups. The first group was discovered in 1937, the last one in 1979. The groups were discovered progressively, first from West toward East along the depositional strike and then downdip. None of the subsequent group was discovered prior to the discovery of the adjacent group. It is possible that other groups remain undiscovered until discovery pattern code is unlocked. Within first five years of each group's discovery, 80% of the reserves (87% NPV) were discovered by 21% of the fields. However, focusing alone on the decreasing size of discoveries in mature play may not represent the true potential of the play. It is the combination of play discovery pattern and the ability to discern betweenEarly Phase, where most of the large size fields (average f eld size; 31 MMBOE) are discovered and the Mature Phase (average field size; 2 MMBOE) can be very powerful tool in exploration strategies. Similar pattern may be observed in other plays and may be useful as additional exploration tools.

AAPG Search and Discovery Article #90987©1993 AAPG Annual Convention, New Orleans, Louisiana, April 25-28, 1993.