The Oklahoma Corporation Commission (OCC) has unveiled additional plans to tackle the problem of earthquakes occurring as a result of hydraulic fracturing in the South Central Oklahoma Oil Province (SCOOP) and Sooner Trend Anadarko Basin Canadian and Kingfisher counties (STACK) oil and gas plays.
As part of the measures, a new protocol was formulated to further reduce the chances of a felt earthquake caused by well completion activities in the plays.
The move comes after the OCC’s Oil and Gas Conservation Division (OGCD) and the Oklahoma Geological Survey (OGS) created a seismicity protocol for operators in December 2016.
The latest protocol seeks to build upon the previous one with further actions.
OGCD director Tim Baker said: “The overall induced earthquake rate has decreased over the past year, but the number of felt earthquakes that may be linked to well completion activity, including hydraulic fracturing, in the SCOOP and STACK has increased.
“Most importantly, the risk of such events appears to be manageable. Learning how to mitigate the risk of causing such events is an ongoing process. The changes we are announcing today are part of that process.”
As per the new amendments introduced in the seismicity protocol, operators in the defined area must use a seismic array in order to record real-time seismicity readings.
The OCC has also reduced the threshold, at which the operator must take action from a 2.5 magnitude (ML) to 2ML.
Operations need to be suspended for a period of six hours if the level reaches 2.5ML against the previous minimum level of 3ML.
Baker further added: “While more study needs to be done, the indications are that those operators who have their own seismic arrays and took actions when there were seismic events too small to be felt decreased the risk of having multiple, stronger earthquakes.”
It is said that less than 4% of detectable, induced earthquake activity in Oklahoma is a result of hydraulic fracturing.
