That makes about 7 earthquakes in the last 8 months.
UPDATE for my loyal Devon Energy reader:
Earthquakes also can be induced by the injection or withdrawal of fluids through wells, as was illustrated by the earthquakes caused by injection of waste fluid from munitions production at the Rocky Mountain Arsenal in the 1960s
From UCLA – According to UCLA one of the big concerns during earthquakes is pipelines! Ut oh! Some slides from a UCLA presentation on induced seismic events and safety: