1. n. [Drilling Fluids]
A type of lost-circulation material that is chunky in shape and prepared in a range of particle sizes. Granular LCM is added to mud and placed downhole to help retard the loss of mud into fractures or highly permeable formations. Ideally, granular LCM should be insoluble and inert to the mud system in which it is used. Examples are ground and sized limestone or marble, wood, nut hulls, Formica, corncobs and cotton hulls. Often, granular, flake and fiber LCMs are mixed together into an LCM pill and pumped into the well next to the loss zone to seal the formation into which circulation is lost.