Method and apparatus for soil mechanics measurements of filter cakes

Abstract From the Canadian patent

An apparatus includes a main housing with a permeable cylindrical sleeve in the main housing to simulate a rock formation through which a well is drilled. A compartment is defined outside the sleeve and a solids-containing fluid is introduced into the interior of the sleeve and pressurized, so that the fluid passes through the sleeve and into the compartment, leaving a filter cake on the inside of the sleeve. A probe extends through the sleeve to simulate a drill string, and the probe can be moved toward and away from the inside surface of the sleeve. The apparatus includes a means for determining the filter cake thickness preferably, ultrasonically.