Wouldn't it be wise to cut off one means for DASH (ISIS) to obtain more money by bombing their money-making oil wells?

The DASH organization makes over $40 million dollars (US) a day on the oil they drill. Why not send a few of the nightly bombs over to their oil fields? I realize that it would begin a fire that would not go out for a time, but if it meant cutting back on what was available monetarily to this group…would it be worth it? Don’t you find it interesting that no one in this melee has touched ANY of the operating oilfields? A few have changed hands, but never shut down. Who set this up? Pollution vs Loss of $ profits for war? (Wonder if the environmental conference is considering this option right now?)