US Patent 10132137 Bidirectional downhole isolation valve

An isolation valve for use in a wellbore includes: a tubular housing; an upper flapper disposed in the housing and pivotable relative thereto between an open position and a closed position; an upper piston operable to open or close the upper flapper; a lower flapper disposed in the housing and pivotable relative thereto between an open position and a closed position; a lower piston operable to open the lower flapper; an opener passage in fluid communication with the pistons and an opener hydraulic coupling; and a closer passage in fluid communication with the pistons and a closer hydraulic coupling.