A self-lubricating sleeve type screw centralizer

Abstract

A self-lubricating sleeve type spiral centralizer comprises a centralizer main body (1), an inner ring body (2) provided on the periphery of the centralizer main body (1) is protruded outward along the radial direction and is formed along the axial direction respectively towards the orientations of both ends and with gradually reducing radius; and a sleeve (3) which is rotatable relative to the inner ring body (2) is sleeved on the periphery of the inner ring body (2). The inner surface of the sleeve (3) and the periphery surface of the inner ring body (2) are adapted to each other and a clearance space is formed therebetween. The sleeve (3) of the self-lubricating sleeve type spiral centralizer disengages from the interior circle body (2) on the centralizer main body (1) and a clearance fit is formed between the sleeve and the inner ring body, and the contact surfaces are studded with composite material or are carried out special process, so that a similar self-lubricating joint bearing structure is formed between the sleeve (3) and the centralizer main body (1), the structure having the performance and specialty of self-lubricating and self-aligning.

Description

technical field [0001] The invention relates to the technical field of geological drilling, in particular to a self-lubricating sleeve type screw centralizer. Background technique [0002] The helical centralizer is a rigid full-bore drilling tool stabilizer. The bottom hole assembly formed by assembling a certain number of helical centralizers at an appropriate position on the drill string can prevent well deviation when drilling a vertical well and control the wellbore trajectory when drilling a directional well. , and can center the drill string to ensure the accuracy of the inclinometer data and improve the stability of the drill bit. [0003] The spiral centralizer of the prior art is to carve several spiral belts according to a certain size on the effective centralizing section of a cylindrical steel body, and then insert a plurality of gage alloy blocks on the spiral belt according to a certain arrangement rule. This structural design can change the flow velocity pro...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a self-lubricating sleeve-type screw centralizer with more reliable working performance and the ability to reduce the risk of pipe sticking, which solves the problems caused by the poor use effect and excessive vibration in the formation with high plasticity in the prior art. The failure of vertical drilling tools and logging while drilling tools

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