Implementation can not take up the wellhead subsea wellhead cap and lifting tools installed

The present invention discloses a method can be implemented without occupying the wellhead and subsea wellhead tool for lifting the cap is mounted, the method comprising the steps of: lifting tool placed on top of the wellhead cap, connecting the tool to achieve a wellhead cap; pneumatic One end of the cable winch connected to the lifting hole on the tool. Start air winch, with the lifting tool into the subsea wellhead cap, under the guidance of an underwater robot, the cap is placed over the wellhead subsea wellhead; spring pin with the subsea wellhead corrosion cap interlock after , AUV extracting and inserting pins, so that lifting the tool and the cap disengaged from a wellhead; reverse air winch, the lifting tools underwater recovery. With the above method, the use of cross practices do not take wellhead subsea wellhead cap installation, saving time operating rod into the cap of the subsea wellhead; ROV observation use to achieve a subsea wellhead installation safety cap; the lifting production tools simple, high reliability.