MPLX is a publicly traded master limited partnership formed by Marathon Petroleum Corporation (MPC) to own, operate, develop and acquire pipelines and other midstream assets related to the transportation and storage of crude oil, refined products and other hydrocarbon based products.
In 2015, MPLX merged with MarkWest, whereby MarkWest became a wholly owned subsidiary of MPLX. MarkWest is one of the largest processors of natural gas in the U.S. and the largest processor and fractionator in the Marcellus and Utica shale plays. The company’s midstream energy operations include: natural gas gathering, processing and transportation; NGL gathering, transportation, fractionation, storage and marketing; and crude oil and refined products transportation and storage. Its integrated midstream energy asset network links producers of natural gas, natural gas liquids and crude oil from some of the largest supply basins in the United States to domestic and international markets.
Through the MarkWest combination, MPLX assets include approximately 5,400 million cf/d of gathering capacity, 7,100 million cf/d of natural gas processing capacity, and 500 mbpd of NGL fractionation capacity and more than 5,000 miles of gas gathering and NGL pipelines. MPLX assets also include 100 percent ownership of common carrier pipeline systems through Marathon Pipe Line LLC (MPL) and Ohio River Pipe Line LLC (ORPL), and a 1 million barrel butane storage cavern in West Virginia. MPLX, through MPL and ORPL, owns, leases and operates 1,008 miles of common carrier crude oil lines and 1,900 miles of common carrier products lines located in nine states as well as four tank farms in Illinois and Indiana with available storage capacity of 4.53 million barrels that is committed to MPC.
MPLX’s inland Marine operations include 18 owned towboats and one leased towboat and a fleet of 205 owned and 14 leased barges. All cargoes transported are liquid and include, among other commodities, crude oil, asphalt, gasoline, diesel fuel, vacuum gas oil, condensate, feedstocks, chemicals and ethanol.