Method and system for controlling rotary tray flexible torque of electric drill

Abstract

The invention provides a control method of a flexible torque of a rotary table of an electric drilling machine and a system thereof. When a drilling string occurs stick-slipping and the torque vibrates, the control function of the flexible torque of the rotary table is started; a torque sensor transfers the collected actual value of the torque of the rotary table to a programmable controller (PLC); the PLC works out the arithmetic average value of the actual value of the torque of the rotary table with n times; the actual value of the torque of the rotary table and the average value are compared, the compared deviation is used as a given disturbing signal of the speed of the rotary table and is used as a given signal of the speed of a speed governor of the rotary table after being superposed with a given signal of the speed of the rotary table so as to control the rotation speed of a main motor of the rotary table and lead the main motor of the rotary table to increase or reduce the speed, thus adjusting the torque of the rotary table. The method and the system thereof can lead the rotation speed of the rotary table to adjust in time with the size of the stick-slipping torque, thus effectively reducing the variable frequency of the torque of the rotary table and the amplitude of the stick-slipping torque, reducing the fatigue failure degree of the drilling string and reducing the probability of drilling accidents due to the fatigue of the drilling string.

Description

technical field [0001] The invention belongs to the technical field of (petroleum) drilling, and in particular relates to a flexible torque control system for a rotary table of a drilling rig adopted after the stick-slip torque vibration occurs in a drill string during drilling operations. Background technique [0002] At present, in the turntable control system of petroleum electric drilling rigs, after the speed of the turntable is set according to the requirements of the drilling process, the torque of the drill string mostly depends on the experience of the driller, and the lowering speed of the drill bit is adjusted to control the drilling pressure to achieve the purpose of adjusting the torque of the drill string In this way, the real-time performance of the torque adjustment of the drill string is poor, and it is easy to cause phenomena such as drill jumping and sticking, which aggravates the fatigue of the drill string, and even causes the consequences of twisting the...

AI Technical Summary

Problems solved by technology

[0002] At present, in the turntable control system of petroleum electric drilling rigs, after the speed of the turntable is set according to the requirements of the drilling process, the torque of the drill string mostly depends on the experience of the driller, and the lowering speed of the drill bit is adjusted to control the drilling pressure to achieve the purpose of adjusting the torque of the drill string In this way, the real-time performance of the torque adjustment of the drill string is poor, and it is easy to cause drill jumping, drill sticking, etc., aggravate the fatigue of the drill string, and even cause the twisting of the drill string or the lower drilling tool.

During the drilling process, the vibration of the drill string is unavoidable. Slight lateral, axial and torsional vibrations do not affect the normal drilling operation, but the stick-slip torque vibration generated in the vertical section of the extended-reach well or the vertical well not only affects the drilling speed, It is also easy to fatigue the drill string, accelerate the damage of the drilling tool, and even induce drilling accidents

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