State officials are reviewing a set of earthquakes from earlier this week and are trying to determine if the earthquakes are related to oil and gas activity.
The Oklahoma Corporation Commission said it is possible that the earthquakes correlate with flowback operations in wells owned by Encana.
Flowback is when a well discharges a mixture of sand, water, natural gas and crude oil over several weeks.
The U.S. Geological Survey said two quakes happened Sunday evening in Kingfisher County with magnitudes of 3.48 and 3.29.
The Journal Record reported the company stopped drilling in July after a couple of earthquakes, then later resumed, but they stopped operations again at the end of October after another series of seismic activity.
A state seismologist said flowback activity does not always correlate with earthquakes and those could be remnants of aftershocks from the July earthquakes.
All of this is still under investigation.