NIOSH’s role in developing ventilation input to new engineering guidelines for shale gas wells influenced by longwall mining

By Steven J Schatzel, geologist, NIOSH

Over the past 18 years, more than 1,500 unconventional shale gas wells have been drilled through current and future coal reserves in Pennsylvania, West Virginia, and Ohio. As gas wells continue to be drilled in underground reserves, the ability for both mining and gas producing activities to coexist safely comes into question. A gas well casing failure resulting from mining-induced ground movements could lead to catastrophic mine explosions and fires. The ventilation and explosions research team, Mine Systems and Safety Branch is conducting research on a hypothetical breach from an unconventional gas well near an operating longwall coal mine and any resulting mine safety consequences. The NIOSH team is providing scientific input to federal and state regulatory agencies as well as the coal and gas industry partners in the development of new guidelines for shale gas wells influenced by longwall mining. This input includes experimental data, analytical methods and interpretations, and numerical and physical modeling tasks. The current findings of this work will be summarized.