Bi-directionally sliding pup-joint coupling centralizer

Abstract

The invention discloses a bi-directionally sliding pup-joint coupling centralizer, which comprises a centralizer body serving as the coupling of a sucker rod. A radial positioning boss is arranged at two ends of the main body respectively; a sleeve-shaped centralizing block is sleeved on the centralizer body between two positioning steps; a helical guide slot is formed on the outer surface of the centralizing block; a rolling bearing is arranged between the inner surface of the centralizing block and the centralizer body; the length of the centralizing block is smaller than the space between the two positioning steps; and the centralizing block can axially move along the centralizer body and axially rotate around the centralizer in the length range limited by the two positioning steps. The number of the centralizing blocks in the coupling centralizer is reduced. Therefore, the ineffective load in the oil extraction process in the oil fields is reduced, the flow area between the coupling centralizer and an oil pipe is increased, and the annular circulation resistance is reduced. Due to the arrangement of the rolling bearing between the centralizing block and the centralizer body, the friction between the coupling centralizer and the oil pipe is reduced, and the passing-through capacity of the coupling centralizer in the oil pipe is improved.

Description

technical field [0001] The invention relates to the technical field of oil and gas production engineering, in particular to a bidirectional sliding nipple collar centralizer for oil production in oil fields. Background technique [0002] About 80% of the production wells in major oilfields in my country use pumping unit oil recovery technology, and the vast majority of coalbed methane wells in my country use the production method of pumping unit drainage and depressurization. Under such working conditions, the workload of oil well pump inspection caused by eccentric wear accounts for about 50% of the total annual workload of pumping well pump inspection. Therefore, it is positive to study the loss of production caused by centralizer to reduce eccentric wear significance. The research on centralizers at home and abroad has a long history, and many different types of centralizer products have been produced. These centralizers are mainly divided into two types, namely collar c...

AI Technical Summary

Problems solved by technology

like figure 1 As shown, the forms of collar centralizers generally have the following types: smooth type, track type, rolling type, limit type, shoulder fixed type, wedge type fixed centralizer, etc. However, the movement mode of these centralizers Basically, the centralizer slides or rolls in one direction, and the friction force under these conditions is relatively large, which increases the load during oil recovery

Images