Abstract

The currently favorable economic and technologic environment for increasing gas production in the U.S. portends an unprecedented boom in the drilling and development of shallow gas plays. Many operators contemplating developing such plays should be aware of the common regulatory, residential, legal, and operator concerns which have surfaced in areas where coalbed methane (CBM) is being produced. These concerns have cost operators millions of dollars spent to both assess the disputed impact of production practices and to settle claims against them. This does not include the hidden costs needed to manage in crisis and redirect a sparse labor pool to handle environmental issues. Many of the claims made against operators could have been foreseen and addressed in more cost-effective ways with a marginal amount of environmental baseline information. But in every case, the absence of baseline data led to considerable controversy and uncertainty regarding whom to blame for a variety of complaints. Fearing a loss of health and safety, local residents chose to blame operators and sought relief through litigation. In this context, prudent baseline measurement and monitoring practices are relatively easy and inexpensive to implement.

This article summarizes the typical environmental complaints commonly attributed to CBM operations in the San Juan, Black Warrior, and Powder River basins over the past two decades. It also provides selected examples of cost-effective methods which operators can use for planning and implementing baseline studies. Without such studies, the task of differentiating between environmental changes caused by production and those resulting from other causes becomes very difficult. Recommended methods focus on understanding production practices from a perspective of the potential impacts on the physical and geochemical properties of regional aquifers. Baseline measurements are best used for assessing risk and targeting areas where health, safety, and quality of life issues are paramount. There are also substantial secondary benefits to these measurements. The right information can help operators to constrain reserboir engineering models, detect reservoir compartmentation and anisotropy, verify the need for infill drilling, assess wellbore integrity, and predict the potential for souring gas reserves.