Recommended Practices for Baseline Sampling of Water Sources in Areas of Shale Oil and Gas Development

Abstract

In many areas of shale oil and gas development, sampling of proximate water sources (e.g., residential water wells, springs, seeps, and surface waters) prior to installation or stimulation of production wells (i.e., “pre-drill”) is standard practice for many oil and gas operators. These programs provide a “baseline” snapshot of water quality for comparison to conditions after oil and gas production commences (i.e., “post-drill”). This information is critical for evaluating whether reported changes in local water quality (e.g., methane, salts) are naturally occurring or the result of nearby drilling activities. Many state agencies require pre-drill and/or post-drill sampling of various water sources (primarily residential water wells); however, little guidance is currently available to operators, regulators, and contractors to support development of these sampling programs. This talk presents the findings of a Department of Energy-funded research project, which evaluated key sources of variability in pre-drill sampling results from a series of residential water wells in Northeastern Pennsylvania and Eastern Kentucky. Results from these field studies culminated in the development of recommended practices for sampling of residential water wells. The recommended practices include: i) current state regulations for pre-drill and post-drill sampling, ii) sampling practices for dissolved gases (i.e., sampling methods, well purging, sample location), and iii) key geochemical lines of evidence to discern natural variability in water quality from potential anthropogenic impacts. This talk provides an overview of the components of the recommended practices, critical findings from the field studies, and implications for development of future pre-drill and post-drill sampling programs in areas of shale oil and gas development.

AAPG Datapages/Search and Discovery Article #90291 ©2017 AAPG Annual Convention and Exhibition, Houston, Texas, April 2-5, 2017