US Patent 10947798 Bidirectional downhole isolation valve

An isolation valve for use in a wellbore includes a housing having a bore; a flapper movable between an open position and a closed position, the flapper operable to isolate an upper portion of the bore from a lower portion of the bore when the flapper is in the closed position; and a collet pivotable between a first position configured to move the flapper to the closed position, and a second position configured to engage the flapper in the closed position, thereby retaining the flapper in the closed position.