Some gas comes from surprise source.

• Position: Your Life - Hydraulic fracturing

Some of the natural gas harvested by hydraulic fracturing operations may be of biological origin--made by microorganisms inadvertently injected into shale by oil and gas companies during the fracking process, a study by Ohio State University, Columbus, has found. The study suggests that microorganisms, including bacteria and archaea, might one day be used to enhance methane production--perhaps by sustaining the energy a site can produce after fracturing ends. The study also is yielding new techniques for tracing the movement of bacteria and methane within wells.

"A lot is happening underground during the hydraulic fracturing process that we're just beginning to learn about," says principal investigator Paula Mouser, assistant professor of civil, environmental, and geodetic engineering. 'The interactions of microorganisms and chemicals introduced into the wells create a fascinating new ecosystem. Some of what we learn could make the wells more productive."

Oil and gas companies inject fluid (mostly water drawn from surface reservoirs) underground to break up shale and release the oil and gas (mostly methane) that is trapped inside. Though they long have known about the microbes living inside fracturing wells--and even inject biocides to keep them from clogging the equipment--nobody has been sure where the bacteria came from, until now.

"Our results indicate that most of the organisms are coming from the input fluid," relates Kelly Wrighton, assistant professor of microbiology and biophysics. "So, this means that we're creating a whole new...