As of September 30, 2011, PVA had approximately 9,700 net acres in Washita County, Oklahoma where we are drilling Granite Wash horizontal wells in a joint venture with our partner, Chesapeake Energy Corp. In addition, we have approximately 40,000 net exploratory acres in various plays in the Anadarko Basin, including the Tonkawa, Cleveland, Granite Wash and other prospect types.
We entered this region in 2006 and had an estimated drilling inventory of up to approximately 80 horizontal Granite Wash drilling locations in the joint venture as of year-end 2010. We operate approximately one-third of the currently drilled joint venture wells and are the operator of the exploratory prospects. We estimate that we had approximately 174 Bcfe of Granite Wash 3P reserves in the joint venture at year-end 2010.