Patent ID: 7915203

Claim:
An inverted emulsion drilling fluid composition comprising: a continuous phase comprising an organic liquid base, a discontinuous phase comprising an aqueous liquid, an emulsifying system, a weight material, and a viscosifying agent, where the emulsifying system comprises a primary emulsifier or a plurality of primary emulsifiers, and a secondary emulsifier or a plurality of secondary emulsifiers, where the secondary emulsifiers comprise alkyl, aryl esters, where the alkyl group, designated R 1 , is a carbyl group having between about 10 and about 40 carbon atoms and the aryl group includes one or more substituents, where the substituents include a halogen atom, R group, SO 3 R 3 group, OPO 2 R 3 group, OPO 3 R 3 group, NHR 2 group, SiH 2 R 2 group, PHR 2 group, SR 2 group or OR 2 group, where R is a carbyl group having between about 1 and about 40 carbon atoms, R 3 is a hydrogen atom or a carbyl group having between 1 and 12 carbon atoms, R 2 is a carbyl group having between about 1 and 40 carbon atoms, and where one or more of the carbon atoms in R, R 1 , R 2 or R 3 can be replaced by B, N, O, Si, P, S, Ge and/or mixtures thereof and one or more of the hydrogen atoms in R, R 1 , R 2 or R 3 can be replaced by F, Cl, Br, I, CONR 2 4 , COOR 4 , OR 4 , NR 2 4 , SR 4 , PR 2 4 , and/or mixtures thereof and where R 4 can be a alkyl, aryl, alkylaryl or arylalkyl group having between 1-20 carbon atoms where one or more carbon or hydrogen atom can be replaced as set forth for R, R 1 , R 2 or R 3 .