Large-torque equal-wall-thickness screw drilling tool with motors in serial connection

Abstract

The invention relates to a large-torque equal-wall-thickness screw drilling tool with motors in serial connection. The drilling tool is mainly composed of a by-pass valve assembly, an anti-falling assembly, a motor assembly, a cardan shaft assembly I, a hollow rotor motor assembly, a cardan shaft assembly II and a transmission shaft assembly; when the drilling tool works, drilling fluid flows to a power part, in the process that the high-pressure drilling fluid moves from an inlet of the motor to an outlet, the water power of the high-pressure drilling fluid is consumed to apply work to a hollow rotor, and the pressure energy of the drilling fluid can be converted into the rotating mechanical energy of the hollow rotor; under the cooperation functions of a solid rotor and the hollow rotor, the whole screw drilling tool weakens the sensitivity of the output rotational speed to the drilling pressure, and compared with an independent solid rotor motor or an independent hollow rotor motor, the drilling tool shows obvious superiority; in cooperation with a centralizer, the drilling tool achieves the function of transferring large torque at a place near a drilling bit, and is suitable for drilling large-displacement directional wells and horizontal wells.

Description

technical field [0001] The invention relates to a high-torque tandem motor equal-wall-thickness screw drilling tool for well drilling, in particular to a high-torque tandem motor equal-wall-thickness screw drilling tool. Background technique [0002] In order to solve the torque problem of drilling deep wells, extended-reach wells, and horizontal wells, drilling workers began to look for ways to increase the power and torque of screw drilling tools for drilling hard formations. It is found that the purpose can be achieved by connecting conventional 2-stage motors in series, so a series motor is produced. The first series motor can drive conventional roller cone bits and diamond bits to drill at the maximum ROP. Although the mechanical drilling speed has increased, the life of the roller cone bit has decreased, so the application rate of the tandem motor is very low. In the early 1980s, polycrystalline diamond compact drill bits appeared, and many companies developed a more s...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is: in order to solve the problems such as the high failure rate of the motor of the existing screw drilling tool and the low output torque, a screw drilling tool with a large torque serial motor and equal wall thickness is designed, which can provide high power, high torque and relatively high torque. High ROP, and can work downhole for a long time, which reduces drilling and tripping operations and reduces drilling costs

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