1. n. [Drilling Fluids]
The salt of aluminum hydroxide and stearic acid (saturated C18 fatty acid) with the formula Al(O2C18H35)3. It is a grease-like solid. When mixed with oil (for example, diesel oil) and the mixture sprayed onto the surface of a foamy water mud, it helps the gas bubbles break out of the mud.
See: defoamer, fatty acid, fatty-acid soap, soap