Device for eliminating circumferential stress of polished rod

Abstract

The invention discloses a device for eliminating the circumferential stress of a polished rod. The device for eliminating the circumferential stress of the polished rod is arranged between balance iron and a beam hanger and comprises an upper supporting piece and a lower supporting piece, the upper supporting piece and the lower supporting piece are arranged in a spherical surface hinged mode, the top face of the upper supporting piece and the bottom face of the lower supporting piece are supporting faces arranged in parallel, a second center hole which is perpendicular to the supporting face and used for allowing the polished rod to penetrate through is formed in the upper supporting piece, and the aperture size of the second center hole is equal to the diameter size of the polished rod; a first center hole which is perpendicular to the supporting face and used for allowing the polished rod to penetrate through is formed in the lower supporting piece, and the aperture size of the first center hole is larger than the diameter size of the polished rod. The device can eliminate the circumferential stress of the polished rod to balance the stress of the polished rod, effectively straighten the polished rod to keep a well mouth centered, prolong the service life of the polished rod and reduce the occurrence of rod breakage accidents, and has important significance for ensuring the production of crude oil.

Description

technical field [0001] The invention relates to the technical field of oil exploitation, in particular to a device for eliminating hoop stress of polished rods. Background technique [0002] During the production and operation of the pumping well, due to the uneven balance iron on the upper part of the rope hanger, the pressure contact of the test pressure sensor installed above the rope hanger is displaced or the contact is damaged, the upper surface of the rope hanger or the pressure sensor is in contact with the balance iron. There is a gap on the side of the polished rod. Under the external force of the polished rod, the gap is forcibly compensated, and the polished rod is bent like a spot, that is, the polished rod is affected by the circumferential stress concentration, resulting in eccentricity, deflection, bending, or even breaking of the polished rod. The polished rod is misaligned at the wellhead. It leads to frequent replacement of oil well packing, and also cause...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to provide a device for eliminating the circumferential stress of polished rods, which can overcome the problems of polished rod damage, breakage, misalignment, production stoppage, and pollution caused by the concentration of circumferential stress in the prior art. The device can eliminate the c

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