Strategic Baseline Groundwater Sampling for Shale Exploration

摘要

Exploration and production from unconventional shale resources has increased significantly in the past several years due to the success of combining horizontal drilling and hydraulic fracturing technologies in a manner that allows natural gas and/or oil to be released from relatively impermeable shale formations. The rapid increase in shale development has raised the concern of landowners and the public that the use of these techniques could adversely impact the groundwater resources in and around the development. In general, there is a lack of real data documenting pre-drill and post-drill conditions that could be used to truly evaluate the impacts of shale development. Using a technically sound strategy to collect data is important in an effort to document baseline environmental and, in particular, groundwater conditions prior to exploration so that post drilling conditions can be evaluated when necessary. The collection of scientifically defensible data for operators involved in the development of a shale play improves stakeholder engagement, protects operators from potential environmental degradation claims, and allows for science-based regulation that truly protects the resources. Collecting a representative set of samples from groundwater supply wells within a defined radius of a well pad prior to drilling activities provides the operator with information that documents pre-drilling groundwater conditions. Performing this type of baseline sampling within a well-designed, scientifically and legally defensible program can help the operator manage and mitigate corporate risk. The public concern over impacts to groundwater must be taken seriously, and adhering to a well designed program that produces science-based results will increase public confidence in the industry's operating practices. This paper presents baseline groundwater sampling program rationale and design based upon existing regulations and experience gained in the United States shale exploration regions.