a base fluid of water or brine various colloidal substances such as clays densifying components such as barite and or special purpose additives such as viscosity modifiers corrosion inhibitors fluid loss control agents thinners and emulsifiers to enable the mud to meet the needs of particular drilling operations these additives increase the density or viscosity of the mud prevent drilling mud loss from the borehole into penetrated formations stabilize mud properties and help keep drill cuttings and debris suspended in the mud preferred silicones for use in this invention include dimethylsiloxane polymers also called dimethyl silicone fluids having the general formula ch 3 2 sio 2 x cyclic or straight chain where x is a number in the range of about 2 to several hundred the viscosity of such dimethyl silicones ranges from about 2 0 centistokes cst considered a low viscosity to about 1 000 cst considered a medium viscosity at 25 u00b0 centigrade emulsifiers are chemical compounds which have both oleophilic and hydrophilic parts examples of emulsifiers suitable for use in this invention include fatty acids soaps of fatty acids and fatty acid derivatives including amido amines polyamides polyamines esters such as sorbitan monoleate polyethoxylate and sorbitan dioleate polyethoxylate imidazolines alcohols polyalkene oxide modified dimethyloiloxanes and combinations or blends of these as the term 34 emulsifiers 34 is used herein it is synonymous or interchangeable with the term 34 surfactants 34 the drilling fluids of the present invention can be prepared in a manner typically used to prepare drilling fluids in one representative procedure for producing a drilling fluid the desired quantity of silicone and an emulsifier are mixed together then other components if any are added sequentially with continuous mixing in practicing the.