| 摘要 |
Well bores are drilled using an invertible oil external-water internal emulsion drilling fluid which is then inverted to a water external-oil internal emulsion by contacting it with an aqueous acid solution containing an anionic sulfonate surfactant for preventing aqueous acid solution-crude oil emulsions and crude oil sludging, and a chemical (eg an ethoxylated amine) for preventing the anionic sulfonate surfactant from rcacting with the emulsifier in the oil external-water internal emulsion. |
