INVERT DRILLING FLUIDS

摘要

There is described an invert emulsion wellbore fluid that includes: an oleaginous external phase; a non-oleaginous internal phase, wherein a ratio of the oleaginous external phase and non-oleaginous internal phase is less than 50:50 by volume; an emulsifier; and a rheological additive comprising a sulphonated polymer formed from 100 to 10,000 monomers. There is also described a method of drilling a subterranean hole using the invert emulsion drilling fluid.