Denver-based MarkWest Energy Partners LP (NYSE: MWE) reports it has constructed a third plant at its Arapaho processing complex in western Oklahoma to serve increasing volumes of liquids-rich gas production from Granite Wash producers, including Newfield Exploration and Linn Energy.

Since expanding its operations in late 2008 to serve producers in the Texas panhandle, MarkWest's throughput volumes from the Granite Wash have increased to nearly 120 million cubic feet per day (MMcf/d) and are forecasted to continue increasing in 2011 and beyond. In addition, MarkWest's producer customers are focusing their drilling plans on the liquids-rich zones in the Granite Wash, which has significantly increased the percentage of rich-gas volumes that MarkWest is gathering and processing.

To support this growth, MarkWest will invest additional capital to expand its rich-gas gathering and compression facilities as well as its Arapaho processing complex. Upon completion of the facility expansions in the third quarter of 2011, the processing capacity at the Arapaho complex will increase by 60 MMcf/d to a total of 220 MMcf/d. The gathering and processing expansions are supported by long-term agreements with producer customers.