Multi-pipe well mouth switching single-pipe well mouth device for three-pipe well mouth and blowout preventer

The utility model provides a multi-pipe well mouth switching single-pipe well mouth device for a three-pipe well mouth and a blowout preventer. The multi-pipe well mouth switching single-pipe well mouth device for the three-pipe well mouth comprises an oil pipe hanger and a well mouth switching part, wherein the oil pipe hanger comprises an upper connecting part and a lower connecting part, a center hole is formed in the oil pipe hanger, the diameter of the center hole is larger than or equal to 300 mm, an auxiliary pipe installation part is arranged in the center hole, the auxiliary pipe installation part is arranged on the inner wall of the center hole and protrudes towards the axis of the center hole, the well mouth switching part comprises a top connecting part and a bottom connecting part, the bottom connecting part is connected with the upper connecting part, the well mouth switching part further comprises a communication hole, the axis of the communication hole is parallel to the axis of the center hole, and the communication hole and the center hole are arranged in a spaced mode. By the adoption of the multi-pipe well mouth switching single-pipe well mouth device for the three-pipe well mouth, multiple oil pipes at the position of a multi-pipe well mouth can be installed at the same time, in this way, an existing blowout preventer used for a single-pipe well mouth can be used for blowout prevention of the multi-pipe well mouth, a multi-pipe well can be repaired directly, and the oil producing efficiency of the multi-pipe well is improved.