THE MARCELLUS SHALE IN WEST VIRGINIA: GEOLOGY, RECENT DRILLING ACTIVITY AND GAS PRODUCTION
The Marcellus thins to the south and west across WV and is not present in southwestern WV, where a regional unconformity results in younger and younger rocks overlying progressively older rocks. The Marcellus is less thermally mature in northwestern WV and southwestern PA, and significant quantities of liquid hydrocarbons, in addition to natural gas, are being produced in this part of the play. More than 3100 wells targeting the Marcellus have been permitted in WV. Horizontal wells, which cost several million dollars to drill, have reported estimated ultimate recoveries of several billion cubic feet (Bcf) of gas. The potential resource has attracted large multinational exploration and production companies to acquire acreage positions within the Marcellus play in keeping with worldwide focus on shale and other unconventional reservoirs. In WV, more than 61 Bcf of gas has been reported as produced from the Marcellus from 2005-2009.