US study sees little earthquake risk from fracking

Fri Jun 15, 2012

* Waste water disposal poses higher risk for quakes      * Only one quake officially linked to fracking      * Best practices protocol should be developed  	      By Ayesha Rascoe	
      WASHINGTON, June 15 (Reuters) - The fracking drilling  technique used to tap shale oil and gas is unlikely to trigger  earthquakes, but underground injection of waste water from  drilling offers more risks for seismic activity, a new U.S.  study said on Friday.	      The National Research Council study, which also examined the  risk of earthquakes associated with tapping geothermal energy  and carbon capture and storage, found that the total balance of  fluid injected or removed underground was the biggest factor in  causing earthquakes related to energy development. 	      "Although induced seismic events associated with these  energy technologies have not resulted in loss of life or  significant damage in the United States, some effects have been  felt by local residents and have raised concern about additional  seismic activity," the council said.	      Researchers have known since the 1920s that injecting or  withdrawing fluids from the ground could cause earthquakes, the  report said, but the issue has come to the fore in recent years  as states such as Arkansas, Ohio and Texas experienced small  tremors associated with waste water disposal from oil and gas  drilling.	       Advances in hydraulic fracturing, or fracking, have  dramatically increased U.S. oil and gas production from shale  formations, but critics have charged that the drilling activity  is polluting the water and air. Opponents of fracking have also  raised concerns about possible earthquakes.	       The council's report said fracking does not pose a high  risk for seismic events, citing only one 2.3 magnitude  earthquake in Blackpool, England that has been officially linked  to fracking for shale gas. 	      "It's refreshing to know that yet another scientific inquiry  has confirmed what all of us who were interested in facts  already knew: there is no legitimate reason to believe hydraulic  fracturing will cause earthquakes," said Steve Everley, of  Energy In Depth, an industry campaign backing shale gas  production.  	      While waste water disposal wells pose more seismic risks,  the report said cases of these wells causing earthquakes  have  been rare and typically less than 5.0 in magnitude.	      "Although the number of felt induced seismic events relative  to the tens of thousands of produced water injection wells is  small, the events themselves can cause considerable public  concern," the report said.	      Kevin Book, an analyst with Clearview Energy Partners, said  in a research note the study's findings on waste water wells may  lead local regulators to require geologic surveys ahead of  disposal well construction. This could add to costs for well  operators.	      Requested by Senator Jeff Bingaman, the Democrat in charge  of the Senate energy committee, the report said more research is  needed to better quantify the risks associated with energy  production and called for development of best practices to help  prevent or mitigate seismic events.   	      The Senate energy committee is scheduled to hold a hearing  on examining the link between earthquakes and energy technology  on Tuesday.	  	   (Reporting by Ayesha Rascoe; editing by Sofina Mirza-Reid and  David Gregorio)