1. n. [Drilling Fluids]

A mud test in which the mud sample is mildly agitated by rolling (or tumbling) for the duration of the test, usually performed at a selected high temperature. Typically, the mud sample is sealed in a mud-aging cell and placed in an oven that will roll (or tumble) the mud cells continually for a given period of time (often 16 hours or overnight). The cooled mud is tested for properties. A rolled (or tumbled) mud sample simulates circulation in the hole by pumping.