Coalbed Methane Produced Water - A Waste or Resource?

Development of unconventional oil & gas reserves such as production of coalbed methane (CBM) has increased dramatically since the mid 1990s.  CBM now accounts for 10% of total natural gas produced in the U.S., most of which (79%) comes from the Rocky Mountain Region.  The shallow exploration targets for CBM require dewatering to extract the gas resource which may impact both ground and surface water supplies.  CBM operators consequently have a produced water disposal issue.

 

CBM wells are typically shallow, and are often completed into the same formations that supply groundwater to wells.  Annual water production in the three main CBM producing basins in Colorado, the San Juan, Piceance, and Raton is in excess of 200 million barrels (26,000 acre-feet).  Costs of produced water disposal vary widely from basin to basin.  The ability to place that water to beneficial use is dependent upon its quality and feasibility for treatment.  Water treatment costs at existing facilities range from $0.25-$2.00/bbl.  The semi-arid west is water short and a producer’s waste may become a water manager’s resource with economic benefits to both parties.

 The administrative and operational considerations for CBM operators recently changed due to the Colorado Supreme Court decision (Vance vs. Simpson/Wolfe) and legislation passed in the 2009 session.  The mere extraction of produced water is now considered a beneficial use, subject to administration (permitting) by the State Engineer and compliance with Colorado water laws.  Reclassification of produced water may create a greater opportunity for beneficial use.