What Does Possum Belly Mean?
A possum belly is a metal container normally installed after the annulus or outlet pipe and before the mud tank or shale shaker on a drilling rig. Its main purpose is to slow the flow of drilling fluid as it returns from the point of drilling up through the annulus. Because the pressure of the mud as it enters the drill string can be as high as 7,500 pounds per square inch it is imperative to slow the flow before the drilling fluid is processed and recycled.
The possum belly may also be referred to as the distribution box or flowline trap.