Mealey's (December 18, 2019, 12:35 PM EST) -- ALEXANDRIA, Va. — An oil and gas company in a Dec. 17 response tells the Patent Trial and Appeal Board that it should confirm as patentable nine claims of a patented pressure actuated sleeve used in the hydraulic fracturing industry (Weatherford International LLC v. Baker Hughes Oilfield Operations LLC, No. IPR2019-00768, PTAB)....