Shale producers in Alberta’s Duvernay region are being asked to monitor and prevent earthquakes after regulators linked a series of seismic events over the last two months to hydraulic fracturing.
Producers must test for quakes and, if they detect seismic events greater than magnitude 2.0 on the Richter scale, take measures to reduce the impact of their activity, the Alberta Energy Regulator said Thursday. If a tremor is detected above magnitude 4.0, producers must immediately halt drilling and can’t resume until they get approval from regulators.
Provincial regulators are blaming fracking for a cluster of 18 quakes with magnitudes as high as 3.7 in December near Fox Creek, Alberta, and several others in January, including one with a magnitude of 4.4. Chevron Corp., Royal Dutch Shell Plc and Encana Corp. are among companies drilling for natural gas liquids in the Duvernay region.
“While these seismic events have not impacted public safety, it is our job to take this precautionary step to ensure energy resources in this area are developed in a safe and responsible manner,” Jim Ellis, chief executive officer of the Alberta Energy Regulator, said in a statement.
Fracking, which has been used in Alberta since the 1950s, includes the pumping of vast amounts of water, sand and chemicals underground at high pressure to free oil and gas from tight rock formations such as shale.
The technique has been tied to earthquakes across North America.
Oklahoma has seen the largest increase in earthquakes that scientists have tied to wastewater disposal from fracking. Last year 585 tremors were registered, according to state figures. Between 1990 and 2008, there were never more than three of magnitude 3.0 or greater in the same year.
–With assistance from Zain Shauk in Houston.
By Rebecca Penty from Bloomberg News on Feb. 20, 2015.