Abstract: A fluid suitable for use as the continuous phase in a drilling fluid is disclosed. The fluid is prepared by the sequential hydrotreating, hydroisomerization and hydrogenation of a crude oil feedstock. The fluid has good low temperature properties, including pour point and accordingly is useable in cold environments. A method of producing the fluid is also disclosed. The fluid may also be used as an additive to a drilling fluid having a continuous aqueous phase wherein it may act as, for example, a rate of penetration enhancer or a spotting fluid. The fluid may also be used as an additive to known drilling fluids such as internal olefins.