Woodford Shale Gas in Oklahoma

Charles W. Wickstrom
Spyglass Energy Group, LLC, Tulsa, OK

The Woodford Shale in Oklahoma has produced hydrocarbons since 1934; however, it was not until 2004 that drilling and completion activity increased from an average completion of 2 wells per year to 35 Woodford completions. In 2007 over 200 horizontal Woodford wells have been drilled and completed. The majority of activity is in the Arkoma Basin with the most successful wells being drilled in Hughes and Coal Counties where the shale is 150' thick. The average maximum month daily rate is reported at 2.5 MMCFG/D and the expected ultimate recovery is estimated to be 3.0 BCFG/Well. The average cost of drilling and completing a horizontal well in the Arkoma Basin in $4.5MM. True vertical depths (TVD) range from 7,500’ to 8,500’ and the laterals average 2,500’ in length. The wells are completed with multi-stage high volume slick-water fracs and casing is cemented to TD. There are six pilot projects underway to determine if this area will be developed on either 80 or 40 acre spacing. In 2007 there are forty-two (42) drilling rigs active in the play in the Arkoma Basin, all drilling horizontal wells. The play is now being extended into two additional basins, the Ardmore and the Anadarko. In the Ardmore Basin the initial concern is that it may not be in the dry gas window. In the Anadarko Basin there are two concerns. The first is the thermally maturity and the second is the depth of burial, TVDs of 12,000’ or more. Vertical and horizontal wells are being drilled and completed in both of these basins and these questions should be answered by the time of this presentation in 2008.

AAPG Search and Discovery Article #90078©2008 AAPG Annual Convention, San Antonio, Texas