External penetrating type rotating magnetic field wellhead sucker rod detection system

Abstract

The invention discloses an external penetrating type rotating magnetic field wellhead sucker rod detection system comprising a three-phase signal generator, an excitation coil, a signal detection coiland a detection data acquisition and processing link. A three-phase signal is accessed to the excitation coil to generate a rotating magnetic field, and the signal detection coil is uniformly wound on a coil fixing device and integrally fixed in the center of a magnetic field generating device; the signal detection coil is connected to a voltage amplifier through a BNC, the voltage amplifier is connected with a lock-in amplifier, and the lock-in amplifier is connected to an acquisition card and finally connected with a computer. The beneficial effects of the external penetrating type rotatingmagnetic field wellhead sucker rod detection system are as follows: the excitation coil can generate a more uniform rotating magnetic field and is sensitive to defects in all directions; the signal detection coil can pick up all axial disturbance signals generated by the defects and is not affected by lift-off; the system is adaptive to sucker rods with different outer diameters; and the accuratepositions of the defects can be determined through a subsequent data processing method.

Description

technical field [0001] The invention belongs to the field of eddy current non-destructive testing, and relates to a wellhead detection system, in particular to an outer-penetrating rotating magnetic field wellhead sucker rod detection system. Background technique [0002] In the petroleum industry, there are many methods of oil extraction, among which mechanical oil extraction is the most important, especially the rod pump, and the rod pumping technology occupies an important position in my country's oil extraction. Therefore, the sucker rod is an important tool in the process of oil well operation. A considerable part of the currently used sucker rods have been working for more than five years. Due to the harsh working conditions and long-term continuous repetitive service, the sucker rods are easily subjected to alternating, vibration and impact loads during use. Fatigue cracks occur. And because of the limited detection technology, equipment conditions and maintenance m...

AI Technical Summary

Problems solved by technology

[0005] In the existing sucker rod wellhead detection technology, the detection signal of the eddy current detection technology is greatly affected by the lift-off effect. The ordinary eddy current detection probe has high requirements for scanning mechanical control, and generally has low efficiency and poor detection effect. Operators have high demands

The most important thing is that most of the current wellhead detection technologies are based on magnetic flux leakage detection technology, which can only detect defects perpendicular to the eddy current direction, and can only locate the defects in the axial direction, but cannot detect the circumferential position of the defects , the joint of the sucker rod cannot be detected

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