Submersible slurry pump can be used for drilling application, mainly to pump the slurry from the mud pit to shale shaker, second to pump the mud to decanter centrifuge( there is another type screw pump to feed for centrifuge, but submersible slurry pump can save place in the tank for compact footprint).
Especially for small drilling applications, such as HDD, they are not closed loop mud tank system, their drilling mud flow to a mud pit first, then use a submersible slurry pump to pump it to the mud system for cleaning. 