Management and Effects of Coalbed Methane Produced Water in the United States

摘要

In some coalbeds, naturally occurring water pressure holds methane-the main component of natural gas-fixed to coal surfaces and within the coal. In a coalbed methane (CBM) well, pumping water from the coalbeds lowers this pressure, facilitating the release of methane from the coal for extraction and use as an energy source. Water pumped from coalbeds during this process-CBM 'produced water'-is managed through some combination of treatment, disposal, storage, or use, subject to compliance with federal and state regulations. CBM produced water management can be challenging for regulatory agencies, CBM well operators, water treatment companies, policy makers, landowners, and the public because of differences in the quality and quantity of produced water; available infrastructure; costs to treat, store, and transport produced water; and states' legal consideration of water and produced water. Some states consider produced water as waste, whereas others consider it a beneficial byproduct of methane production. Thus, although current technologies allow CBM produced water to be treated to any desired water quality, the majority of CBM produced water is presently being disposed of at least cost rather than put to beneficial use. The Energy Policy Act of 2005 (P.L. 109-58, Section 1811) noted the relevance of CBM produced water and directed the Bureau of Land Management (BLM) to enter into an agreement with the National Research Council (NRC) to evaluate CBM produced water management in six western states. The NRC established the Committee on Management and Effects of Coalbed Methane Development and Produced Water in the Western United States to develop this report, which addresses the study charge. The report specifically examines the Powder River, San Juan, Raton, Piceance, and Uinta CBM basins in the states of Montana, Wyoming, Colorado, New Mexico, and Utah.