Device and method for undercutting liner hanger controlled by cable with trigger communication

Abstract

The invention discloses a drilling liner hanger releasing device and method adopting cable tie trigger communication control. The drilling liner hanger releasing control method comprises the steps that a, the upper end of the drilling liner hanger releasing device is connected with a drill rod, the lower end of the drilling liner hanger releasing device is connected with a lifting sub, and the lifting sub is connected with a drilling liner hanger; b, connected pipe strings in the step a are downwards put into a drill well, when the drilling liner hanger is located on an operation position, a cable is downwards put from a wellhead, the lowermost end of the cable is provided with a downhole trigger, the downhole trigger is in a starting state before being downwards put into the well, the downhole trigger is sent to the same well-depth position as the automatic releasing device, and resistance wires are arranged in the downhole trigger to generate heat continuously; and c, a temperature sensor is arranged in the drilling liner hanger releasing device, and when the temperature monitored by the temperature sensor exceeds the temperature threshold value set in advance, the drilling linerhanger releasing device conducts releasing. By adopting the drilling liner hanger releasing device and method, the problems that the drill rod is too long, consequently torque transmitting is not inplace, and a downhole thread cannot be completely loosened can be avoided.

Description

technical field [0001] The invention relates to the technical field of drilling in oil and gas fields, in particular to an undercut device and method for a liner hanger controlled by communication with a cable belt trigger. Background technique [0002] When drilling in the oil field, during the liner cementing process, when the liner is put in place, before cementing, it is necessary to loosen the thread connecting the upper drill pipe and the liner hanger. The currently used liner hanger generally adopts the method of rotating the drill pipe at the wellhead to transmit the torque to the thread connecting the drill pipe and the liner hanger through the drill pipe, so as to realize the successful undercut and loosen the drill pipe. Thread for connection to liner hanger. 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 lin...

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