On the six acres we have under lease only a small amount has activity the rest do not. Does the lease expire on the land that has no actitivty?
Is the entire 6 acres included in the drilling unit? Also, what exactly do you mean by "small amount of activity"? There is a chance that all of your 6 acres is NOT locked into the "activity" you have occurring - but it depends on the details of your situation and your lease content.
As background, what are your particulars regarding your lease?; location, lease basics (bonus, term, royalties), lease holder (producer).