Abstract: A riser pressure relief apparatus includes a pressure relief valve with a valve member, an actuator, and a pilot valve assembly connected to a pressurized fluid. The valve member moves between a first position, which prevents a fluid flow through the side port, and a second position, which permits the flow. The actuator includes an open port and moves the valve member from the first to the second position by supplying the pressurized fluid to the open port. The pilot valve assembly moves between a first configuration, which prevents a flow of the pressurized fluid to the open port, and a second configuration, which permits the flow. A valve part of the pilot valve assembly moves from a first to a second position based on a fluid pressure in the riser, which causes the pilot valve assembly to move from the first to the second configuration or vice versa.

Abstract: A method of operating a drilling system. The drilling system includes a drill string extending into a wellbore, a driver which rotates the drill string, a pump to pump drilling fluid down the drill string, a wellhead mounted at the wellbore, a riser extending up from the wellhead around the drill string, a blowout preventer mounted on the wellhead, a riser closure device mounted in the riser, a first return conduit, and a flow outlet arranged in the riser below the riser closure device. The method includes operating the driver to stop a rotation of the drill string, closing the riser closure device if it is not already closed, operating the pump to stop a pumping of drilling fluid down the drill string, closing the blowout preventer, and increasing a wellbore pressure by controlling a rate of the flow of the fluid along the first return conduit.

Abstract: A riser pressure relief apparatus includes a pressure relief valve with a valve member, an actuator, and a pilot valve assembly connected to a pressurized fluid. The valve member moves between a first position, which prevents a fluid flow through the side port, and a second position, which permits the flow. The actuator includes an open port and moves the valve member from the first to the second position by supplying the pressurized fluid to the open port. The pilot valve assembly moves between a first configuration, which prevents a flow of the pressurized fluid to the open port, and a second configuration, which permits the flow. A valve part of the pilot valve assembly moves from a first to a second position based on a fluid pressure in the riser, which causes the pilot valve assembly to move from the first to the second configuration or vice versa.