MarkWest Announces Major Expansion of Processing and Fractionation Infrastructure in Butler County, PA

DENVER--(BUSINESS WIRE)--MarkWest Energy Partners, L.P. (NYSE: MWE) (“MarkWest” or “the Partnership”) announced today a major expansion of midstream infrastructure at its Keystone complex in Butler County, Pennsylvania, to support growing rich-gas production from the Marcellus Shale and Upper Devonian formations. The expansion will be supported by new agreements with Rex Energy Corporation (NASDAQ: REXX) (“Rex Energy”) and EdgeMarc Energy (“EM Energy”). As part of these agreements, MarkWest will construct Bluestone III and IV, both of which are 200 million cubic feet per day (MMcf/d) plants that are expected to begin operations during the fourth quarter of 2015 and the second quarter of 2016, respectively. In addition, the Partnership will construct 40,000 barrels per day (Bbl/d) of additional de-ethanization capacity and over 20,000 Bbl/d of additional propane and heavier NGL fractionation capacity.