20090186781 | Drilling fluids comprising sub-micron precipitated barite as a component of the weighting agent and associated methods - An embodiment of the present invention includes 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 precipitated barite having a weight average particle diameter below about 1 micron and a particle having a specific gravity of greater than about 2.6. Another embodiment of the present invention includes a drilling fluid comprising: a carrier fluid; and a weighting agent that comprises precipitated barite having a weight average particle diameter below about 1 micron, and a particle having a specific gravity of greater than about 2.6. Another embodiment of the present invention includes a weighting agent that comprises precipitated barite having a weight average particle diameter below about 1 micron, and a particle having a specific gravity of greater than about 2.6. | 07-23-2009 |