| 20120028855 | SHALE HYDRATION INHIBITION AGENT(S) AND METHOD OF USE - A method of using water-based drilling fluid in a subterranean formation containing shale which swells in the presence of water by circulating a water-based drilling fluid into the formation. The drilling fluid is made of an aqueous based continuous phase, a weighting material, and a shale hydration inhibition agent (SHIA) comprising deep eutectic solvents (DES) formed by the reaction of a first compound comprising an ammonium compound, and a second compound comprising at least one of amides, amines, diamines, cyclic amines, cyclic diamines, and combinations thereof. The SHIA is present in an amount sufficient to reduce shale swelling. A method of reducing shale swelling during wellbore drilling that includes providing a water-based drilling fluid comprising an aqueous based continuous phase, a weighting material, and a SHIA comprising DES formed by the reaction of a quaternary ammonium compound, and a diamine; and circulating the drilling fluid into the subterranean formation. | 02-02-2012 |
