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

DENVER--(BUSINESS WIRE)--

MarkWest Energy Partners, L.P. 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 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.

The Keystone complex currently consists of the Bluestone processing and fractionation complex and the Sarsen processing facility which combined currently provide 210 MMcf/d of processing capacity and 26,500 Bbl/d of fractionation capacity. The Keystone complex is anchored by Rex Energy and in May 2014, MarkWest began operations of the 120 MMcf/d Bluestone II plant and 10,000 Bbl/d each of ethane and propane plus fractionation capacity to continue supporting Rex Energy's growing rich-gas production. In addition to the new Bluestone processing and fractionation plants, the Partnership completed a 32 mile purity ethane pipeline connecting the Bluestone facility to Sunoco's Mariner West pipeline project.

In conjunction with additional processing and fractionation infrastructure, MarkWest continues to develop its rich-gas gathering system throughout Butler County and surrounding areas in order to support the growth of its producer customers' production.

“Our expansion of the Keystone complex is very strategic to producer activity in Beaver, Butler and surrounding counties and we are very excited to continue building our strong relationship with Rex and begin supporting EdgeMarc,” stated Frank Semple, Chairman, President, and Chief Executive Officer of MarkWest. “Since our acquisition of the Keystone assets over two years ago, volumes continue to increase significantly and we are leading the development of full-service midstream services in the highly prospective rich-gas areas of the northwest Marcellus.”

MarkWest Energy Partners, L.P. is a master limited partnership engaged in the gathering, processing and transportation of natural gas; the gathering, transportation, fractionation, storage and marketing of natural gas liquids; and the gathering and transportation of crude oil. MarkWest has a leading presence in many unconventional gas plays including the Marcellus Shale, Utica Shale, Huron/Berea Shale, Haynesville Shale, Woodford Shale and Granite Wash formation.

This press release includes “forward-looking statements.” All statements other than statements of historical facts included or incorporated herein may constitute forward-looking statements. Actual results could vary significantly from those expressed or implied in such statements and are subject to a number of risks and uncertainties. Although MarkWest believes that the expectations reflected in the forward-looking statements are reasonable, MarkWest can give no assurance that such expectations will prove to be correct. The forward-looking statements involve risks and uncertainties that affect operations, financial performance, and other factors as discussed in filings with the Securities and Exchange Commission (SEC). Among the factors that could cause results to differ materially are those risks discussed in the periodic reports filed with the SEC, including MarkWest's Annual Report on Form 10-K for the year ended December 31, 2013. You are urged to carefully review and consider the cautionary statements and other disclosures made in those filings, specifically those under the heading “Risk Factors.” MarkWest does not undertake any duty to update any forward-looking statement except as required by law.