High performance drilling fluids with submicron-size particles as the weighting agent

摘要

Methods and compositions utilizing a drilling fluid comprising sub-micron precipitated barite having a weight average particle diameter below about 1 micron. Methods include a method comprising circulating a drilling fluid in a well bore, wherein the drilling fluid comprises: a carrier fluid; and a weighting agent that comprises sub-micron precipitated barite having a weight average particle diameter below about 1 micron are disclosed. In some embodiments, the drilling fluid may comprise an invert emulsion. In some embodiments, the sub-micron precipitated barite has a particle size distribution such that at least 10% of particles in the sub-micron precipitated barite have a diameter below about 0.2 micron, at least 50% of the particles in the of the sub-micron precipitated barite have a diameter below about 0.3 micron and at least 90% of the particles in the sub-micron precipitated barite have a diameter below about 0.5 micron.