High-Yield Drilling Clay
High-Yield Drilling Clay : A classification given to a group of commercial drillingclay preparations having a yield of 30 to 50 bbl/ton and intermediate between bentonite and lowyield clays. High-yield drilling clays are usually prepared by peptizing low-yield calcium montmorillonite clays or, in a few cases, by blending some bentonite with the peptized low-yield clay. (Bul D11)