Tony,

I have also been curious about the series of quakes that seem to be in the same location, a bit east or NE of Oklahoma City if I recall correctly (internet on ship very slow, is 5 AM, can't use at all except late night, so have not checked the 4.4). A couple of months ago I checked to see if they are producing "tight" gas (from shale), where they fracture the rock to produce, which could trigger quakes, but I the shale gas region seems to be different.
One might wonder if this is leading to a larger quake; an old advisor published a theory that quakes like New Madrid were related to fluid in the lower crust and that you get increasing small quakes then some large ones then it gradually calms down and is done.

Chris