Abstract: A process for the preparation of triphenylmethane dye of the formula ##STR1## wherein R.sub.1 and R.sub.2 each denote hydrogen, C.sub.1 -C.sub.4 alkyl, benzyl or sulfobenzyl,R.sub.3 and R.sub.4 each denote hydrogen, C.sub.1 -C.sub.4 alkyl or sulfonic acidR.sub.5 denotes a phenyl, sulfophenyl, dialkylaminophenyl, C.sub.1 -C.sub.4 alkylphenyl, C.sub.1 -C.sub.4 alkyl-dialkylaminophenyl, halogenophenyl, naphthyl, sulfonaphthyl, disulfonaphthyl, or alkyldisulfonaphthyl by oxidation of the leuco compound of the corresponding triphenylmethane dye with manganese dioxide in the presence of an aqueous phosphoric acid at a temperature of about 20.degree. C. to about 100.degree. C.,by the addition of a base selected from the group consisting of ammonia, amines, aminoalcohols, metal hydroxides of Groups IA, IIA, IIIA and mixtures thereof in an amount sufficient to neutralize the aqueous solution,by filtration from the precipitate andby isolation of the triphenylmethane dye.

Abstract: An improved oil-base drilling fluid comprising a continuous oil phase and a dispersed internal phase using aqueous non-halide salt solutions is described. Preferably, the non-halide salt is potassium acetate, calcium acetate, sodium proprionate or combinations thereof, however, citrate, tartrate, or gluconate salts may also be used. Emulsifiers, wetting agents, and other chemicals may be added in varying concentrations to achieve desired characteristics for the drilling fluid. The composition has suitable rheological properties, stability, and hole cleaning abilities for use as a drilling fluid; and it is more compatible with environmentally acceptable land disposal methods than conventional oil-base drilling fluids used in land drilling applications.