A Possum belly, on a drilling rig, is a metal container at the head of the

shale shaker Shale shakers are components of drilling equipment used in many industries, such as coal cleaning, mining, oil and gas drilling.They are the first phase of a solids control system on a drilling rig, and are used to remove large solids ( cutting ...

that receives the flow of

drilling fluid In geotechnical engineering, drilling fluid, also called drilling mud, is used to aid the drilling of boreholes into the earth. Often used while drilling oil and natural gas wells and on exploration drilling rigs, drilling fluids are also us ...

and is directly connected to and at the end of the

flow line {{for, the molding defect, Flow marks A flow line, used on a drilling rig, is a large diameter pipe (typically a section of casing) that is connected to the bell nipple (under the drill floor) and extends to the possum belly (on the mud tanks) a ...

. A possum belly may also be referred to as a distribution box or flowline trap. The purpose of the possum belly is to slow the flow of the

(after it has gained momentum from coming down through the

) so that it does not shoot off of the

s. Possum bellies are generally used when bentonite or another form of "mud" is being used. During the use of

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include ...

brine water Brine is a high-concentration Solution (chemistry), solution of salt (NaCl) in water (H2O). In diverse contexts, ''brine'' may refer to the salt solutions ranging from about 3.5% (a typical concentration of seawater, on the lower end of that of ...

, the

generally either goes straight to the reserve pit, or into the steel pits. The possum belly derives its name from the similarity of its appearance to the underbelly of the female possum. Each of the chambers of the possum belly resemble an elongated teat similar to the ones found on female possums.

References

{{Reflist, colwidth=30em Oilfield terminology Drilling technology Petroleum engineering