* Comments: 

VOC: VOC Energy Trust owns a term net profits interest of the net proceeds from production of the interests in oil and natural gas properties in the states of Kansas and Texas. It owns an 80% term net profits interest of the net proceeds on the underlying properties. As of December 31, 2009, the underlying properties produced oil from approximately 892 gross (550.2 net) wells located in 193 fields; and had total proved reserves of 13.0 million barrels of oil equivalent. The company was founded in 2010 and is based in Austin, Texas.

QRE: QR Energy, LP, through its subsidiary, QRE Operating, LLC, engages in the acquisition, production, and development of onshore crude oil and natural gas properties in the United States. As of March 31, 2011, its properties consisted of working interests in 2,140 gross producing wells located in Alabama, Arkansas, Kansas, Louisiana, New Mexico, Oklahoma, and Texas. QRE GP, LLC operates as the general partner of the company. QR Energy, LP was founded in 2006 and is based in Houston, Texas.

MMLP: Martin Midstream Partners L.P. provides various petroleum products and by-products, and related services in the United States Gulf Coast region. It operates in four segments: Terminalling and Storage, Natural Gas Services, Sulfur Services, and Marine Transportation. The Terminalling and Storage segment owns or operates 27 marine shore based terminal facilities and 12 specialty terminal facilities that provide storage, processing, and handling services for producers and suppliers of petroleum products and by-products, lubricants, and other liquids, including the refining of various grades and quantities of naphthenic lubricants and related products. This segment also provides land rental services to oil and gas companies, and storage and handling services for lubricants and fuel oil. The Natural Gas Services segment engages in gathering and processing of natural gas, and distributes natural gas liquids (NGLs). This segment owns a NGL pipeline; and three NGL supply and storage facilities, as well as has ownership interests in approximately 706 miles of gathering and transmission pipelines located in the natural gas producing regions of East Texas, Northwest Louisiana, the Texas Gulf Coast and offshore Texas, and federal waters in the Gulf of Mexico. The Sulfur Services segment processes and distributes sulfur produced by oil refineries that is used in the production of fertilizers and industrial chemicals. This segment own and operates six sulfur-based fertilizer production plants, and one emulsified sulfur blending plant that manufacture sulfur-based fertilizer products for wholesale distributors and industrial users; and one sulfuric acid production plant that processes molten sulfur into sulfuric acid. The Marine Transportation segment utilizes a fleet of 44 inland marine tank barges, 18 inland push boats, and 4 offshore tug barge units that transport petroleum products and by-products. The company was founded in 2002 and is based in Kilgore, Texas.