Tool Introduction:

During the well repair operation, from the dismantling of the Christmas tree to the installation of the riser and blowout preventer group, the downhole safety valve is in a "closed" state due to the disconnection of the control pipeline, resulting in the loss of the reverse circulation function of the downhole pipe and the inability of the pipe string to solve complex downhole situations (such as stuck drilling requiring unblocking, falling and cutting, etc.); If, in order to keep the underground safety valve in a controlled state, it is necessary to reconnect the control pipeline. So before installing the anti spray device group, the control pipeline must be reconnected again. But once the control pipeline is reconnected, effective pressure testing of the blowout preventer group cannot be carried out, which does not meet the safety requirements of well control. In the current severe security situation, it is urgent to address this issue. So, the current operational status is: either the downhole string does not have the function of reverse circulation to solve complex situations, or there are no conditions for pressure testing of the blowout preventer group, and only one of the two can be chosen. Therefore, it is urgent to conduct research and improvement on the current downhole tubing to fundamentally solve the problem of choosing between the two and achieve the goal of both.

It can replace the function of the downhole safety valve. At this time, the downhole safety valve can be fully opened. When reverse circulation of the pipe column is required, positive pressure can be added from the wellhead to make the plate valve of the wellhead safety valve open.

Structural features:

① The pawl structure can lock the spindle after it descends;

② The plate valve design has a self balancing function;

③ Simple structure, reliable performance, and easy operation.

operation

Apply positive pressure to the wellhead and cut off the shear pin of the wellhead safety valve, causing the spindle to descend. The spindle opens the 210 ball on the plate valve assembly, balancing the up and down pressure of the plate valve; After the upper and lower pressure of the plate valve is balanced, continue to apply pressure to the tool diameter to make the spindle descend and open the plate valve; After the plate valve is fully opened, the elastic claw opens in the groove of the upper joint, locking the plate valve assembly in a always open state;

Technical parameters: