METHOD OF FORMULATING AND USING A DRILLING MUD WITH FRAGILE GELS

摘要

A method for drilling, running casing, in, and/or cementing a brothel in a subterranean formation without significant loss of drilling fluid is disclosed, as well as compositions for use in such method. The method employ s a drilling fluid comprising a fragile gel or having fragile gel behavior and providing superior oil mud rheology and overall performance. The fluid is especially advantageous for use in deep water wells because the fluid exhibi ts minimal difference between downhole equivalent circulating density and surfa ce density notwithstanding differences in drilling or penetration rates. When a n ester and isomerized olefin blend is used for the base of the fluid, the flu id makes an environmentally acceptable and regulatory compliant invert emulsion drilling fluid. The fluid preferably contains no organophilic clays.