A method for measuring near-drilling torque in gas drilling

Abstract

The invention discloses a gas drilling near-bit torque measuring method. The method includes that two non-magnetic drill collars are arranged axially on a near-bit drill string on the lower portion of a drill string through a drill rod at an interval, a direction detector is arranged in each non-magnetic drill collar and provided with a corresponding microwave transmission relay, and each direction detector transmits a monitored direction value to the ground in real time through the corresponding microwave transmission relay; in the process of drilling, the drill rod of the near-bit drill string peripherally deforms under action of torque, and a torque value received by the drill rod meets a following relation, wherein T refers to the torque value received by the drill rod of the near-bit drill string, G refers to shear modulus of the drill rod of the near-bit drill string, dphi / dx refers to change rate of torsion angle along the length direction, A refers to cross section area of the drill rod of the near-bit drill string, and p refers to a distance between a certain point on cross section of the drill rod of the near-bit drill string and the circle center. By the method, working conditions of a near-bit area can be reflected really, timely, reliably and accurately.

Description

technical field [0001] The invention relates to gas drilling technology, in particular to a gas drilling near-drilling torque measurement method. Background technique [0002] In the construction of gas drilling, in order to be able to grasp the status of downhole work during the production process, it is necessary to obtain real-time changes in the torque of the lower part of the drill string in the wellbore, that is, the torque change of the drill string near the drill string (the drill string close to the drill bit). This is to judge whether there are dangerous working conditions such as pipe sticking and well wall collapse in the downhole. [0003] At present, the torque information measurement of the near-drilling drill string in gas drilling is usually carried out on the ground, that is, a torque sensor is arranged on the drill string driving rotary table and / or the upper part of the drill string, so that by reading the data obtained by the torque sensor, the downhole ...

AI Technical Summary

Problems solved by technology

Although this near-drilling drill string torque information measurement method is simple and convenient, its main technical problem is: since the drill string in the wellbore is composed of multiple drill pipes and drill collars connected axially joint by joint, it is often long The length of each drill pipe and drill collar is usually about 9 meters, and each drill pipe is an elastic deformation body; , drill bit, drilling tool assembly, wellbore shape, weight on bit, speed, pump stroke, drilling fluid performance and surface machinery, etc., the force is complex, and its absolute At the same time, because it is difficult to determine the corresponding relationship with various factors, the absolute value of the final measured torque of the drill string near the drill string is mostly inaccurate, and it is often related to the actual torque value of the drill string near the drill string. Larger deviation, it is difficult to judge the intensity of torsional vibration of the drill string near the drill

[0004] It can be seen that the existing near-drilling drill string torque measurement technology for gas drilling has the technical problems of poor measurement timeliness and accuracy, and thus cannot achieve stable high torque control on the drill string during the drilling process, which is not conducive to reducing drilling tool accidents. The minimum control system is also not conducive to improving the rate of penetration of gas drilling

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