MarkWest Energy Partners LP, Denver, will expand midstream infrastructure at its Keystone complex in Butler County, Pa., the company said, to handle growing rich-gas production from the Marcellus shale and Upper Devonian formations.
New processing agreements with Rex Energy Corp. and EdgeMarc Energy will underwrite the expansion. As part of these agreements, MarkWest will build Bluestone III and IV, each of which to handle 200 MMcfd and to begin operations in fourth-quarter 2015 and second-quarter 2016, respectively.
In addition, MarkWest will build 40,000 b/d of additional de-ethanization capacity and more than 20,000 b/d of additional propane and heavier NGL fractionation capacity.
The Keystone complex currently consists of Bluestone processing and fractionation and Sarsen processing, which combined provide 210 MMcfd of processing capacity and 26,500 b/d of fractionation capacity (OGJ, June 9, 2014, Newsletter).
The Keystone complex is anchored by Rex Energy. MarkWest in May began operations of the 120-MMcfd Bluestone II plant and 10,000 b/d each of ethane and C3+ fractionation capacity to continue handling Rex Energy’s growing rich-gas production. In addition to the Bluestone processing and fractionation plants, MarkWest completed a 32-mile purity ethane pipeline connecting Bluestone to Sunoco Logistics Partners LP’s Mariner West pipeline.