Abstract: A managed pressure drilling (MPD) system including a work string including tubulars having an internal flow path. The work string supports a liner float. A liner hanger running tool is coupled to the work string uphole of the liner float. An MPD sub is coupled to the work string and is operable to close off the internal flow path to fluid pressure passing uphole from the liner float in a first position and opens the internal flow path to fluid pressure after the liner string reaches a target depth. The MPD sub includes a housing having a rotatable ball valve including a ball. A ball seat is arranged between the rotatable ball valve and the downhole end, and a ball engagement member arranged between the rotatable ball valve and the uphole end. The ball engagement member includes a seal component that engages the ball portion.

Abstract: A managed pressure drilling (MPD) system includes a work string having one or more tubulars having an internal flow path. The work string supports a liner string terminating in a liner float. A liner hanger running tool is coupled to the work string uphole of the liner string and the liner float. A selectively operable surge control sub is arranged uphole of the liner hanger running tool, and a selectively operable MPD sub is positioned uphole of the liner hanger running tool and the selectively operable surge control sub. The selectively operable MPD sub is operable to close off the internal flow path to fluid pressure passing uphole from the liner float in a first position during MPD operations and opens the internal flow path to fluid pressure after the liner string reaches a target depth.