While environmentalists and some citizens are opposed to the use of hydraulic fracturing (fracking) to develop shale natural gas, experts -- one of whom has studied fracking for more than 41 years -- told a Senate committee the practice does not negatively impact drinking water or the environment.
"There is no question that shale gas resources can be developed in a manner utilizing horizontal drilling and multi-stage hydraulic fracturing that protects the environment and minimizes the impact on nearby communities," said Mark D. Zoback, geophysics professor at Stanford University, during a hearing of the Senate Energy and Natural Resources Committee.
"In my opinion, current drilling and hydraulic fracturing activity in the shale gas [basins] does not really affect drinking water aquifers," said Stephen A. Holditch, head of the petroleum engineering department at Texas A&M University. "I've been working on hydraulic fracturing for over 40 years. My master's thesis in 1970 was on hydraulic fracturing...and there's absolutely no evidence that fractures can grow from miles under the ground up to the surface to the aquifer."
Zoback and Holditch -- along with Daniel Yergin, chairman of IHS Cambridge Energy Research Associates; and Kathleen McGinty, senior vice president of Weston Solutions Inc. -- sat on the Secretary of Energy Advisory Board (SEAB) Natural Gas Subcommittee, which released a report in mid-August that made a number of recommendations, including that industry measure the volume and composition of fluids being pumped into gas wells, as well as the volume and composition of the flowback (see Shale Daily, Aug. 12).
Holditch believes that fracking has gotten a bad rap. "If you read recent news articles on hydraulic fracturing, the process is often described as pumping in a mixture of water and toxic chemicals under high pressure under the earth. This description is far from the truth," Holditch said. "Most fracture treatments consist of 99.5% pure water and sand," and "only 0.5% chemicals," he told the Senate panel. The chemicals include gelling agents, such as those that are used in a lot of food products; surfactants, such as Dawn liquid soap; and biocide, or Clorox bleach.
Most of the concerns about the safety of shale gas development have nothing to do with fracking but rather involve leakage along well casing, spills and blowouts, Zoback said. As a result, "hydraulic fracturing has become a bumper sticker for everything that we need to watch out for."
In the ongoing Environmental Protection Agency review of fracking, Holditch said the agency has focused on five or six case histories where there was reported groundwater contamination of fresh water aquifers. It intends to "study those in great detail and try to find out exactly what happened" and whether fracking was the culprit, he said. The study's findings are expected to be out in either spring or summer 2014.
Holditch said "shale gas is for real." It accounts for 30% of the natural gas consumed in the United States. The Department of Energy has reported that more than 900 Tcf is technically recoverable just in the shale gas plays that have been developed in the past five or 10 years.
"The way to convert it from technically recoverable to economically recoverable is to increase the technology used to extract the gas so we can get more gas out per well and reduce the cost per well," Holditch said.
All of the experts agreed that the reins of regulation of fracking should stay in the hands of the states. "We [subcommittee members] didn't come up with any conclusion that the deck chairs needed to be shuffled," McGinty said.
"I think there is a very strong fabric there" with the existing state regulation of the industry, Yergin said. If federal regulation of the industry were added, "certainly you can end up having a superstructure on top of a superstructure that would make investment more difficult, taking much longer to get things done."
There are several areas in fracking where more research is needed. The industry needs to improve the technology to recycle water, Holditch said. It also needs to improve the chemistry of the fracture fluid additives so it can use salt water for fracking rather than fresh water.
Yergin calls for "very modest funding" by the federal government to support a state review of oil and gas environmental regulations, and targeted federal research and development support to develop technologies that address the environmental issues and promote continuous improvement in best practices.