Patent ID: 7094738
Filing Date: 2006-08-22
Classification: C09K,C10M

Abstract:
1. A method of drilling a subterranean formation utilizing an aqueous based drilling fluid, wherein the drilling fluid is composed of an aqueous base fluid, and a weighting agent, wherein the weighting agent is a salt selected from the group consisting of alkali metal halides, alkali metal nitrates; alkali metal sulfates, alkali metal formates; alkali metal acetates, alkali metal propionates, alkaline earth metal halides, alkaline earth metal nitrates; alkaline earth metal sulfates, alkaline earth metal formates; alkaline earth metal acetates, alkaline earth metal propionates, rare earth metal halides, rare earth metal nitrates; rare earth metal sulfates, rare earth metal formates; rare earth metal acetates, rare earth metal propionates, transition metal halides, transition metal nitrates; transition metal sulfates, transition metal formates; transition metal acetates, transition metal propionates, and combinations thereof, wherein the improvement comprising, adding an effective amount of one or more phospholipid to substantially reduce the coefficient of friction when compared to the fluid absent the phospholipids, and wherein the phospholipid has the structure: in which R and R′ are C