METHODS AND AQUEOUS BASED WELLBORE FLUIDS FOR REDUCING WELLBORE FLUID LOSS AND FILTRATE LOSS

摘要

Embodiments disclosed herein relate to aqueous based wellbore fluids for preventing wellbore fluid loss downhole containing at least one graft copolymer formed from at least one natural polymer and styrene copolymer and 1,3-butadiene, wherein the at least one natural polymer is polysaccharide, and an aqueous base fluid. A method is also disclosed for drilling a wellbore using an aqueous based wellbore fluid.