Modified nanoclays: An approach to stabilizing drilling fluids rheology at high temperature

Keeping in view the decisiveness of drilling fluids impact on drilling efficiency, this work presents an approach to stabilize the drilling fluid rheology in high temperature and pressure conditions by making use of modified nano-clays. An abundantly available clay in Oman, attapulgite was tested in purified nano-form (0.3 nm diameter) for its effectiveness to tailor the rheology of drilling fluids swiftly, that are able to retain their properties over a wide range of operating temperatures, thus ensuring efficient operation in versatile formations. Sufficient experiments were performed to compare the rheology of drilling fluids containing Bentonite only, which is a common drilling fluid additive, with drilling fluids containing bentonite in presence of small quantities of attapulgite nanoparticles. After successive experiments an absolute proportion of water, bentonite and attapulgite nanoparticles was found out that gives consistent results at various temperatures i.e. stable drilling fluid rheology. The best recorded results are reported in this paper and me properties focused here are me plastic viscosity, gel strength, yield point and density.