Patent ID: 7745380

Claim:
A method of treating a wellbore, the method comprising: circulating a wellbore fluid in the wellbore, wherein the wellbore fluid comprises an oleaginous base fluid and a wellbore additive colloidal solid material, wherein the wellbore additive colloidal solid material is formed by grinding a solid particulate material and a polymeric dispersing agent for a sufficient time so that the polymeric dispersing agent is absorbed to the surface of the resulting colloidal solid particles, wherein the grinding is carried out in the presence of an oleaginous base fluid and a dispersing agent selected from the group consisting of oleic acid, polybasic fatty acids, alkylbenzene sulphonic acids, alkane sulphonic acids, linear alpha-olefin sulphonic acids, the alkaline earth metal salts of any of the above acids, phospholipids, synthetic polymers, and combinations thereof, and wherein the grinding is carried out so that the wellbore additive colloidal solid material has a weight average particle diameter d 90 less than 2.0 microns.