(1) (N.) Drilling Fluids. A Mud in Which The External Phase is A Product Obtained From An Oil, Such As Diesel Oil Or Mineral Oil. See: Aniline Point Test, Attapulgite, Brine, Bypassed Mud, Calcium Chloride, Calcium Test, Chenevert Method, Chloride Test, Coalescence, Colloid, Creaming, Diesel-Oil Mud, Dispersion, Drilling Fluid, Electrical Stability Test, Fatty Acid, Fatty-Acid Soap, Flash Point, Hectorite, High-Pressure, High-Temperature Viscometer, Hydrophile-Lipophile Balance Number, Hygrometer, Inhibit, Inhibitive Mud, Interfacial Tension, Invert-Emulsion Oil Mud, Lignite, Oil-Base Mud, Oil-Mud Emulsifier, Oil/Water Ratio, Organophilic, Organophilic Lignite, Pour Point, Rheology Modifier, Shale, Sheen Test, Slurry, Surface Tension, Suspended Solids, Synthetic-Base Mud, Synthetic/Water Ratio, Water-In-Oil Emulsion. (2) (N.) Drilling Fluids. More Generally, A Mud System That Has Any Type of Nonaqueous Fluid As The External Phase. This Definition Would Include The Newer Variety of Oil Muds That Are More Exactly Defined As Synthetic-Base Muds. Synthetic Mud is Analogous To Oil Mud. See: Diesel-Oil Mud, Invert-Emulsion Oil Mud, Oil-Base Mud, Syn, Synthetic-Base Mud