Dislocated support-type centering guide for cased well logger

Abstract

The invention discloses a dislocated support-type centering guide for a cased well logger. The dislocated support-type centering guide for the cased well logger is characterized in that support arms, ejector rods, springs and socket sleeves are adopted to form a lever structure. When the inner diameter of a casing pipe is slightly changed, the support arms rotate, forces received by the springs are not changed much, and moment arms of the springs are nearly unchanged, so that support forces of rollers are nearly unchanged by the buffering and the compensation of lever mechanisms; all rollers are centripetally arranged, so that the centering performance of the centering guide is better; two sets of centering arms are dislocated in an axis direction, so that the centering guide is more stable, and can more easily overcome obstacles. A positioning boss located on a center rod is capable of preventing the phenomenon that the support arms at both sides of each roller are damaged due to the fact that the support arms are excessively close, and meanwhile, the positioning boss also plays a role of limiting the sliding socket sleeves. The dislocated support-type centering guide for the cased well logger disclosed by the invention is suitable for casing pipes of various specifications. By rotating threads between glands and slide carriages, the length of an inner gap between each socket sleeve and the corresponding gland is adjusted to control magnitudes of the forces of the springs, and therefore, the magnitudes of the support forces can be adjusted according to the size of the inner diameter of the casing pipe in actual logging operations.

Description

technical field [0001] The invention relates to a centralizing device of a petroleum logging instrument, in particular to a misalignment supporting centralizer of a casing well logging instrument. Background technique [0002] In the cased hole logging operation, the logging tool needs to be located in the center of the casing, so the centralizer is a commonly used auxiliary equipment for downhole logging, especially in horizontal well logging. The logging tool works in a horizontal state. If the logging tool cannot be effective Living in the center of the casing will seriously affect the logging effect and even lead to logging failure. In the horizontal state, the centralizer bears the entire weight of the logging instrument, and the centralizer is required to provide a large supporting force; during the transportation of the logging instrument in the horizontal well section, the smaller the friction resistance of the centralizer, the smaller the required transmission power...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to overcome the disadvantages of existing centralizers such as easy jamming during well logging, inability to measure in pits in wells, serious wear of rollers or roller pins, and provide a centralizer with simple structure, convenient maintenance and low cost of use. Dislocation support centralizer for cased hole logging tool

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