PROTECTING METHOD AND CONTROLLER FOR ROTARY DRILLING RIG, PROTECTING SYSTEM AND ROTARY DRILLING RIG

摘要

Disclosed in the present invention is a protecting method for a rotary drilling rig; the rotary drilling rig includes a drilling pipe (5) and a main pump (1) for driving the drilling pipe (5) into rotation, wherein the protecting method includes detecting a depth of the drilling pipe (5) and a first output pressure of a main pump (1); determining a first upper limit value according to the value of the depth, comparing the value of the first output pressure with the first upper limit value, and lowering the first output pressure of the main pump (1) when the value of the first output pressure is larger than the first upper limit value. Also provided in the present invention are a controller to perform the above mentioned protecting method, a protecting system and a rotary drilling rig. By means of detecting and performing feedback of the output pressure value of the main pump, the above mentioned technical solution reduces the output of the main pump and lowers the actual torque when the actual torque borne by the drilling pipe is larger than the maximum torque sustainable thereby, thus preventing deformation of the drilling pipe.