Device and method for undercutting liner hanger controlled by current carrier

Abstract

The invention discloses a current carrier-controlled tail pipe hanger reverse device and method. The method includes the steps that a, the upper end of the tail pipe hanger reverse device is connectedto a drill pipe, the lower end of the tail pipe hanger reverse device is connected to a lifting pup joint, and the lifting pup joint is connected to a tail pipe hanger; b, a ground signal generator and a ground electrode are arranged on the ground, the ground electrode is connected with a wellhead, the ground electrode is used as a pole, the wellhead is connected with a downhole tubular column asa pole to form an alternating current oscillation circuit, a pipe string of which connection is completed in step a is sent down into a drilling well, when the tail pipe hanger is located at the working position, the ground signal generator generates an alternating current carrier control command, namely a current signal flows down along the downhole tubular column; c, after the tail pipe hangerreverse device receives the alternating current carrier control command generated by the ground signal generator in step b, reversing action is performed. The device and the method can avoid the problem that a downhole thread cannot be completely disengaged due to the fact that the torque transmission is not in place caused by the excessive length of the drill pipe.

Description

technical field [0001] The invention relates to the technical field of oil and gas field drilling, in particular to a device and method for inverting a liner hanger controlled by a current carrier. Background technique [0002] During oilfield drilling, in the process of liner cementing, when the liner is in place and before cementing, it is necessary to loosen the thread connecting the upper drill pipe and the liner hanger. When the current liner hanger is inverted, it is generally used to rotate the drill pipe at the wellhead, and the torque is transmitted to the thread connecting the drill pipe and the liner hanger through the drill pipe, so as to achieve successful inversion and loosen the drill pipe. Thread to attach to tailpipe hanger. The biggest problem with this method is that since the wellhead is several kilometers away from the downhole liner hanger, when the drill pipe is rotated on the ground, it is difficult to accurately transmit the torque to the drill pipe...

AI Technical Summary

Problems solved by technology

The biggest problem with this method is that since the wellhead is several thousand meters away from the downhole liner hanger, it is difficult to accurately transmit the torque to the drill pipe and the liner hanger due to the elastic deformation of the drill pipe itself when the drill pipe is rotated on the ground. At the thread of the connection, it is often encountered that the rotating drill pipe on the ground is in place, but the thread connecting the downhole drill pipe and the liner hanger is not completely loosened, which will cause follow-up blind construction and even lead to downhole complex situations

Images