Patent attributes
A fast-acting managed pressure drilling rig is disclosed. A main valve configured as an alternative for a conventional rotating control device is provided to control drilling of a wellbore. A second valve is configured to trap pressure in the wellbore. A choke valve maintains well bottomhole pressure within specified limits by trapping pressure or by releasing trapped pressure within the wellbore. A pressure relief choke is configured to provide fine pressure stability control within the well and to act as a pressure relief valve in response to wellbore overpressure. A controller is configured with at least one processor to affect operation of the main valve, the second ratio valve, the choke valve, and the pressure relief choke in response to information received by the controller representing operation of the managed pressure drilling rig.
