Development of wellhead pressure protection device in offshore drilling

Currently offshore oil drilling and completion operations are conducted in batch mode, which means that, when a batch of holes are drilled to total depth, the crew will turn to completion operations. This mode has some potential safety hazards, such as oil/ gas spill from both inside and outside the pipe; meanwhile, accidents like kicks and blowout may occurd due to the fact that the tubing spool, Christmas tree and blind flanges have not been installed at this point, so the pressure inside casing cannot be controlled. In view of the above situations, we have developed an offshore drilling wellhead pressure protection device, which can be directly installed on the casing head or tubing spool after drilling is finished for easy and fast monitoring of the well pressure changes; in case of flow or kicks, we can kill the well and restore downhole safety; Moreover, the device can prevent small things from falling into wells so to ensure safe operation. This offshore drilling wellhead pressure protection device is of compact structure with favorable sealing property, easy operation and stable and reliable performances, which has filled up the gap in offshore oilfield wellhead protection, significantly improved the safety of batch drilling and completions.