Diameter-changing and friction-reducing drill column centralizer

Abstract

The invention relates to a diameter-changing and friction-reducing drill column centralizer which comprises an upper connector, a lower connector, an inner tubular column and an outer tubular column. The inner tubular column is internally connected between the upper connector and the lower connector, and the outer tubular column is externally connected between the upper connector and the lower connector; a tapered barrel is sleeved between the upper connector and the lower connector in a sliding and sealing mode, the tapered barrel is formed by integrating a cylinder section and a circular cone section, and the outer diameter of the lower portion of the circular cone section is tapered; a tension spring is sleeved on the inner tubular column on the upper side of the tapered barrel, and the tapered barrel is connected to the lower portion of the upper connector through the tension spring; a through hole is arranged on the tubular wall of the inner tubular column on the upper portion of the tapered barrel; a plurality of punched holes are circumferentially arranged on the tubular wall of the outer tubular column in a ring mode, a centralizing column is arranged in each punched hole in a sealing and sliding mode, an inner end surface of the centralizing column contacts with an outer surface of the circular cone section of the tapered barrel and is provided with a contact surface which is matched with the outer surface of the circular cone section; and a flange is arranged on the outer wall of the centralizing column in a ring mode, and a compressed spring is sleeved between the flange and the inner wall of the outer tubular column. By means of the centralizer, outer diameters can be real-timely attached to a well wall, centering degrees, drilling qualities and efficiencies of a drilling rod in a drilling well can be improved, and the centralizer is provided with a friction-reducing function.

Description

technical field [0001] The invention relates to a downhole tool for oil drilling, in particular to a diameter-reducing and wear-reducing drill string centralizer which is suitable for using drilling fluid as a circulation medium in oil drilling. Background technique [0002] In drilling operations such as horizontal drilling, directional drilling, and conventional drilling in oil and gas fields, due to the action of complex forces such as gravity and the interaction force between the drill bit and the formation, the drill string is prone to deflection or lies on the downhole wall, making it difficult to center , seriously affecting the drilling quality. The diameter of the centralizing block of the conventional drill string centralizer cannot be changed, and the centralization accuracy is not high. It has limited effect on improving the centering degree of the drill string, and it cannot play a centralizing role at all in the loose well section and the well wall expansion se...

AI Technical Summary

Problems solved by technology

[0002] In drilling operations such as horizontal drilling, directional drilling, and conventional drilling in oil and gas fields, due to the action of complex forces such as gravity and the interaction between the drill bit and the formation, the drill string is prone to deflection or easy to lie on the well wall, making it difficult to center , which seriously affects the drilling quality

The diameter of the centralizing block of the conventional drill string centralizer cannot be changed, and the centralization accuracy is not high, which has a limited effect on improving the centering degree of the drill string, and can not play a centralizing role at all in the loose well section and the well wall expansion section

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