Discharge of Coalbed-Methane-Produced Waters Into Limited Capacity Waters: An Evaluation of the Wyoming Experience and a Possible Resolution

Eric L. Hiser and Matthew Joy
Jorden Bischoff McGuire Rose & Hiser, PLC, Scottsdale, AZ

Natural gas production from coal bed methane has expanded dramatically in the Powder River Basin area of Wyoming. The rapid rise in the number of coal bed methane wells and the corresponding need to handle produced water has given rise to local concern about the impact of the water on available water resources and has led to efforts to constrain handling options. This presentation briefly looks at the nature of the concerns, industry efforts to respond to those concerns, alternative methods of handling coal bed methane produced water such as direct discharge, containment in on- and off-channel reservoirs and pits, irrigation and other beneficial uses, treatment, and reinjection. The presentation evaluates the various alternative handling methods, their advantages, disadvantages and constraints, and recommends an approach that maximizes the flexibility to use the best mix. The presentation then outlines a mixed approach emphasizing the use of available assimilative capacity in the Powder River and discusses how to create systems to make the assimilative capacity reasonably available while protecting the environment and how to allocate those resources equitably and efficiently from an economic perspective. The approach presented is presently under discussion for potential use in the main stem Powder River watershed in Wyoming.

AAPG Search and Discovery Article #90039©2005 AAPG Calgary, Alberta, June 16-19, 2005