Solid residue that accumulates on a borehole wall as drilling filtrate penetrates into the formation. Mudcake can become thick enough to limit the ability of dipmeters and imaging tools, in particular bore hole televiewers, to acquire meaningful data from the borehole wall. The presence of thick mudcake (detected with calipers) is often used as an indicator of large formation permeability.
See also mud, bit size, calipers.