Profile: MarkWest Energy Partners, L.P. (MWE.N)

MarkWest Energy Partners, L.P. is a master limited partnership engaged in the gathering, compressing, treating, processing and transportation of natural gas; the transportation, fractionation, storage, and marketing of natural gas liquid (NGLs), and gathering and transportation of crude oil. The Company operates in three segments: southwest segment, gulf coast segment and northeast segment. On February 21, 2008, MarkWest Energy Partners, L.P. completed its plan of redemption and merger (the Merger) with MarkWest Hydrocarbon, Inc. and MWEP, L.L.C., a wholly owned subsidiary of the Partnership, pursuant to which MarkWest Hydrocarbon, Inc. was merged into the partnership. On January 22, 2009, the Company entered into an agreement to form a joint venture with an affiliate of NGP Midstream and Resources, L.P. During the year ended December 31, 2008, the Company acquired the subsidiary of PetroQuest Energy, L.L.C. (PetroQuest).

The Company owns a 50% non-operating membership interest in Starfish Pipeline Company, L.L.C. (Starfish), whose assets are located in the Gulf of Mexico and Southwestern Louisiana. It also owns a 40% non-operating membership interest in Centrahoma Processing, L.L.C. (Centrahoma).

The Company provide services in the midstream sector of the natural gas industry which includes natural gas gathering, transportation, processing and fractionation. The natural gas gathering process begins with the drilling of wells into gas bearing rock formations. Once completed, the well is connected to a gathering system. Gathering systems consist of a network of small diameter pipelines and, if necessary, compression systems, that collects natural gas from points near producing wells, and transports it to the pipelines for further transmission. Natural gas has varying composition, depending on the field, the formation reservoir or facility from which it is produced. The principal constituents of natural gas are methane and ethane. The natural gas also contains varying amounts of heavier components, such as propane, butane, natural gasoline and inert substances that may be removed by any number of processing methods.

Natural gas processing and treating involves the separation of raw natural gas into pipeline-quality natural gas, principally methane, and NGLs, as well as the removal of contaminants. Raw natural gas from the wellhead is gathered at a processing plant, typically located near the production area, where it is dehydrated and treated, and then processed to recover a mixed NGL stream. In case of the Javelina facilities, the natural gas delivered to the processing plant is a byproduct of the crude oil refining process.

Southwest Segment

The East Texas system consists of natural gas gathering pipelines, centralized compressor stations, a natural gas processing facility and an NGL pipeline. The East Texas system is located in Panola, Harrison and Rusk Counties and services the Carthage Field. Producing formations in Panola County consist of the Cotton Valley, Pettit and Travis Peak formations, which collectively form one of the natural gas producing regions in the United States. Approximately 82% of the natural gas volumes in the East Texas System result from contracts with five producers. The Company sell substantially all of the purchased and retained NGLs produced at the East Texas processing facility to Targa Resources Partners, L.P. (Targa) under a long-term contract.

The Company owns the Foss Lake natural gas gathering system and the Arapaho I and II natural gas processing plants, all located in Roger Mills, Custer and Ellis Counties of Western Oklahoma. The gathering portion consists of a pipeline system that is connected to natural gas wells and associated compression facilities. All of the gathered gas ultimately is compressed and delivered to the processing plant. The Company has constructed a 60-mile pipeline from the Foss Lake system to the Granite Wash formation in the Texas panhandle and plan to build new gathering and compression infrastructure in the area. It also owns the Grimes gathering system, which is located in Roger Mills and Beckham Counties in Western Oklahoma. In addition, the Company owns a natural gas gathering system in the Woodford Shale play in the Arkoma Basin of Southeast Oklahoma.

The Company owns a number of natural gas-gathering systems located in Texas, Louisiana, Mississippi and New Mexico, including the Appleby gathering system in the City and County of Nacogdoches, Texas. In addition, the Company owns four lateral pipelines in Texas and New Mexico.

Northeast Segment

The Company is the processor of natural gas in the Appalachian Basin, with fully integrated processing, fractionation, storage and marketing operations. The Appalachian assets include the Kenova, Boldman, Cobb and Kermit natural gas processing plants, an NGL pipeline, the Siloam NGL fractionation plant and two caverns for storing propane. The Northeast segment operations include MarkWest Hydrocarbon, Inc.

The Company owns and operates a crude oil pipeline in Michigan, known as the Michigan Crude Pipeline. The Michigan Crude Pipeline is subject to regulation by the Federal Energy Regulatory Commission (FERC). It also own a natural gas gathering system in Michigan.

Gulf Coast Segment

The Company owns and operates the Javelina Processing Facility, a natural gas processing facility in Corpus Christi, Texas, which treats and processes off-gas from six local refineries. The facility processes approximately 120 to 130 million cubic feet of natural gas per day (MMcf/d) of inlet gas out of its 142 MMcf/d capacity.