Threaded nipple for heavy oil thermal recovery well

Abstract

The invention discloses a threaded nipple for a heavy oil thermal recovery well. The threaded nipple comprises an external threaded joint and an internal threaded joint which are engaged with each other; threaded sections of the external threaded joint and the internal threaded joint are improved based on API (American Petroleum Institute) standard buttress thread; ledge faces are respectively formed at the threaded tail end of the internal threaded joint and the end part of the external threaded joint; the ledge face of the internal threaded joint and the ledge face of the external threaded joint form a buckling match structure; the ledge faces comprise right-angle ledge faces and asymmetrical V-shaped ledge faces; the right-angle ledge faces are formed at the internal wall of the threaded nipple and vertical to the center line of the threaded nipple; and the V-shaped ledge faces comprise ledge inclined surfaces I and ledge inclined surfaces II which are connected with each other. According to the threaded nipple for the heavy oil thermal recovery well, through the arrangement of the asymmetrical V-shaped ledge faces and the right-angle ledge faces, one faces of the V-shaped ledge faces are always in close contact under the action of high torque and big bend, so that the safety and reliability of the threaded nipple in heavy oil thermal recovery operation under the condition of high torque and big bend are improved.

Description

technical field [0001] The invention relates to the technical field of oil drilling, development and production, and more specifically relates to a special threaded joint for heavy oil thermal recovery wells. Background technique [0002] Due to the excellent sealing performance of API round thread and the high tensile strength of trapezoidal thread, these two threaded joints are widely used. However, strings in harsh wells such as deep wells, ultra-deep wells, extended-reach wells, horizontal wells, and high-temperature, high-pressure gas wells are subject to complex forces, and threaded joints must bear complex loads. Traditional API round threads and partial trapezoidal threads can no longer meet their use requirements. Excellent special threaded joints began to be researched and applied. In recent years, special threaded joints with sealing surfaces and flat shoulders have begun to be used in thermal recovery of heavy oil. However, due to the influence of high temperatu...

AI Technical Summary

Problems solved by technology

[0005] In order to solve the problem that threaded joints cannot withstand high torque and large bending in heavy oil thermal recovery, and improve the safety and reliability of threaded joints in heavy oil thermal recovery operations, the invention provides a special threaded joint for heavy oil thermal recovery wells, Described technical scheme is as follows:

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