The Arkansas Oil and Gas Commission (AOGC) has extended a moratorium on the drilling of new disposal wells in the Fayetteville Shale by six months while it collects data to determine whether disposal activities contributed to hundreds of small earthquakes in the area.
In December a 30-day emergency order banned new disposal wells on fears that tremors in the area were at least partially caused by the injection of well flowback into existing wells. There are currently seven disposal wells operating in the moratorium area, which is 576 square miles in Faulkner County. Applications are pending for two more wells.
During the six-month period, the AOGC will collect data on daily activities from injection well operators. "...[A]ll operators of existing class II commercial disposal wells or class II disposal wells [are required] to submit bi-weekly reports detailing the daily amounts of barrels of water injected per zone and the maximum daily injection pressure per zone..." the December emergency order stated.
The data will be studied by the Arkansas Geological Survey, AOGC Director Larry Bengal told NGI's Shale Daily.
"We will be basically studying the relationship of injection disposal activity in the injection wells in reference to the seismic events, trying to determine if there is a correlation between the injection activity and the seismic events," Bengal said. "The problem with this whole issue is it is an historically active seismic area to begin with, before the Fayetteville Shale was ever discovered and produced."
During the 1980s parts of Arkansas experienced seismic activity that was deemed to be naturally occurring. "There was never any known definitive reason why that occurred. There was no oil and gas drilling anywhere in the area. That activity went away," Bengal said. The latest seismic activity, which started last summer in the Fayetteville, is showing similar characteristics, he said.
The findings of the study are expected to be taken up at AOGC's July 28 meeting.