Abstract

The Midcontinent of the United States has multiple Carboniferous petroleum systems that illustrate a wide range of unconventional play types. These plays include hydrocarbons produced from:

1. Source shales with minimal migration(Woodford & Springer plays)

2. Tight reservoirs adjacent to source rocks (Meramec, Sycamore, and Granite Wash plays)

3. Long transition zones in tight reservoirs filled by long distance migration (Mississippi Lime)

4. Dewatered-depressurized dual porosity carbonate reservoirs (Hunton dewatering play)

Three years ago Warwick Energy Group was faced with a familiar problem, where and how to concentrate a limited capital budget to provide the best returns to our investors. Working closely with engineering we built a data base of more than 600 type curves for all the major plays in the US to identify the commercial core of each play. Critical success factors were mapping entire petroleum systems with attention paid to rock & fluid properties as well as normalizing production data to a per foot basis. We then considered acreage situations in terms of access, activity, and pricing. Lastly we assessed operational risk related to water injection and triggered seismicity. We identified the STACK play in Oklahoma (Sooner Trend Anadarko Canadian Kingfisher) as an emerging play in which Warwick could leverage Oklahoma’s pooling laws during low commodity prices to acquire non-operated working interests. The STACK play includes the Woodford shale and overlying Meramec siltstones –these are partly self-sourced. These formations dip into the basin from a normal-pressured light oil window to an overpressured volatile oil window into strongly overpressured wet gas and dry gas windows. The Meramec ranges from 50m to 200m in thickness and has multiple benches. Our forensic technical work permitted area specific valuations. More importantly, we realized the core of the play was further west than most activity which enabled us to get ahead of acreage price escalation. There are now more than 40 rigs running in the STACK, which is the second most active play in the US behind the Permian basin. In two years Warwick has become the sixth largest company in the STACK, has a climbing production base approaching 10,000boepd, and is participating in 50% of the all wells being drilled in the core of the play.