Eagle Rock Energy Partners is a limited partnership engaged in the following two businesses: Midstream, which focuses on gathering, compressing, treating, processing, transporting, marketing and trading natural gas, fractionating, transporting and marketing natural gas liquids, and crude oil and condensate logistics and marketing; and Upstream, which focuses on developing and producing oil and natural gas property interests. As of Dec 31 2013, Co.'s estimated net proved reserves in the Upstream business were 346.30 billion cubic feet equivalent, which consisted of 177.20 billion cubic feet of natural gas, 13.5 million barrels (MMBbls) of oil, and 14.6 MMBbls of natural gas liquids.