Regional Correlations and Gas Well Recovery -Vs- Depth Studies in the Anadarko Basin Area of Western Oklahoma

Paul W. Smith, Walter J. Hendrickson, Craig M. Williams, and Thomas J. Woods

To investigate the industry assumption that individual well recovery is merely a function of depth (increased pressure), a cooperative study between the Gas Research Institute and Dwight's Energydata Inc. was conducted. The Anadarko Basin was selected as the site of these investigations because of the wide distribution of producing depths observed in the basin and because of favorable data availability throughout the basin. Furthermore, several formations are amenable to evaluation through a wide range of depths. However, the nomenclature used within the Anadarko Basin and encompassing shelf areas is typically erratic. An estimated 35% of the wells with an operator-defined producing reservoir were incorrect. Therefore, detailed log cross-sections were constructed to insure a proper re ervoir production allocation for each well. All the producing gas wells within a study area from T9-29N,R10-26W (12,852 square miles) were examined - about half the Anadarko Basin.

This study evaluates the relationships existing between gas well recovery and depth. The results of this investigation indicate that reservoir characteristics have a more pronounced effect on formation productivity than does depth (pressure). Also, components of the study identified discrepancies in the recovery/depth relationships based upon formation lithology and by various formations which have similar lithologies. The statistical results of the studies and the regional log cross-sections generated are presented.

AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California