Use of Esters of carboxylic acids as complex surfactants in emulsion MUDs to sweep oil based Drilling and other agents for the treatment of drilling Rig.

摘要

The description relates to the use of complex esters from the reaction of: (a) di and/or tricarboxylic acids or their derivatives capable of ester formation; with (b) polyvalent alcohols with up to 6 and preferably with up to 4 OH groups and/or their oligomers; and (c) monocarboxylic acids; which have an initial molar ratio b/a somewhat corresponding to the number of carboxyl groups per mol of reactant (a), are largely free of unreacted carboxyl groups but may have residual free OH groups, as ecologically acceptable emulsifiers of the W/O type in fluid and pumpable drilling muds or other borehole treatment agents which have a dispersed aqueous and/or water miscible alcoholic phase in a closed oil phase and are suitable for the environmentally friendly opening of deposits, e.g. of petroleum or natural gas. The invention also relates to invert drilling muds which are suitable for the environmentally friendly opening of geological deposits and contain, in a closed oil phase, a dispersed aqueous and/or water miscible alcoholic phase together with emulsifiers and other customary auxiliaries, e.g. thickening agents, fluid-loss additives, fillers, water-soluble salts and alkaline reserves, characterized by the fact that, together with an ecologically acceptable closed oil phase, they contain surface-active complex esters of the kind described above as emulsifiers or emulsifier components.