Fast drilling invert emulsion drilling fluids

摘要

Disclosed are invert oil emulsion drilling fluids containing a non-toxic, biodegradable oil having a viscosity at 25 DEG C. of less than 1.5 centipoise, a flash point of at least 60 DEG C., an aniline point of at least 80 DEG C., and a content of aromatic hydrocarbons of less than 1% by volume. These drilling fluids have a low viscosity at the high shear rates imparted to a drilling fluid at the bit during drilling. This low bit viscosity provides for faster penetration rates. Such drilling fluids containing a temperature stabilizing additive exhibit superior thermal stability.