ANTI-ACCRETION ADDITIVES FOR DRILLING FLUIDS

摘要

Additives for drilling fluids, in particular for water-based drilling fluids are described which when added to the fluid at levels of up to 10 % weight by volume reduces the accretion and bit-balling tendencies of shale cuttings exposed to said fluids. The additives are based on phosphonate chemistry, and are of the general class (I), wherein R, R' and R'' are radicals exclusively containing H atoms or combinations of H, C, O or P atoms up to a maximum of 100 atoms.