| 摘要 |
A method of operating a drilling system, the drilling system comprising a drill string 34, a driver 23, a pump 33, a well head 4, a riser 5 and a blowout preventer (BOP) 3. The BOP has a sealing element which engages with the drill string when the BOP is operated to close around the drill string, a riser closure device, a return conduit and a flow outlet. The method comprises the steps of, after determining that there is or may be a need to close the BOP, implementing a control procedure comprising the following steps: a) operating the driver to stop rotation of the drill string, b) closing the riser closure device (if not already closed), c) operating the pump to stop the pumping of mud into the drill string, d) closing the blowout preventer, characterised in that the method further includes the step of e) increasing the wellbore pressure by controlling the rate of flow of fluid along the return conduit. |
