A production logging flexible sub

Abstract

A flexible pup joint for production logging is formed by sequential and serial connection of a first sealing component, a first buffering component, a flexible component, a second buffering component and a second sealing component. The flexible component is formed by series connection of a plurality of flexible sections, and each two adjacent flexible sections are capable of rotating axially and swinging flexibly to change flexibility of a production logging tool string. Flexibility index can be adjusted by quantity change of the flexible sections, and the buffering components at two ends of the flexible component have an anti-impact function. A wire arranged in the flexible pup joint for production logging in a communicated manner can be communicated with a wire in the production logging tool string, so that the problem of wire passing is solved. The flexible pup joint for production logging can be inserted to any position of the production logging tool string and plays a role in guiding when being mounted at the bottom end of the production logging tool string. Furthermore, the flexible pup joint for production logging can adapt to deformation of an oil pipe or a logging environment with an irregular annular space between the oil pipe and a sleeve, the success rate of descending for production logging is increased, and instrument safety is protected.

Description

technical field [0001] The invention belongs to the technical field of petroleum well logging, and relates to an auxiliary tool for production logging, in particular to a production logging flexible sub-joint. Background technique [0002] During the production logging operation, the casing and tubing will be deformed due to the change of formation pressure and various wellbore operations, which may cause the production logging tool to run into the well. In oil regions such as Changqing, Xinjiang, and North China, more than half of the production logging failures were caused by obstructions in wells. [0003] Due to the small diameter and light weight of the production logging tool, at present, most of the domestic and foreign countries use a weighted nipple to increase the weight of the tool string, so as to try to reduce the probability of the tool running into obstruction. However, although the weighted sub-joint increases the weight of the instrument, it increases the l...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a production logging flexible nipple, which can solve the problem that the production logging instrument encounters obstacles in going downhole due to the deformation of the tubing and casing.

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