Airtight seal sleeve joint

Abstract

The invention discloses an airtight seal sleeve joint. The airtight seal sleeve joint comprises a sleeve male end and a sleeve female end, the sleeve male end is provided with an external thread, the sleeve female end is provided with an internal thread, the external thread of the sleeve male end is meshed with the internal thread of the sleeve female end, and the tooth profile of the external thread and the tooth profile of the internal thread are each of a slanting trapezoid shape. In addition, in the feeding direction of the external thread, the part, behind the external thread, of the sleeve male end is provided with a first seal face and a first retreat stop shoulder connected with the first seal face, and the first retreat stop shoulder is located at the tail end of the sleeve male end. The sleeve female end is provided with a second seal face and a second retreat stop shoulder, the second seal face is in interference fit with the first seal face, the second retreat stop shoulder is matched with the first retreat stop shoulder, and the second seal face is also connected with the second retreat stop shoulder. A gap is formed between the internal thread and the external thread. The airtight seal sleeve joint has good stretch resistance, compression resistance and torque resistance capability, better thread gluing resistance and excellent airtight seal performance and can adapt to the work environment of a three-exceeding gas field.

Description

technical field [0001] The invention relates to an oil casing joint, in particular to a partial trapezoidal casing joint. Background technique [0002] At present, the existing casing joints can be roughly divided into two categories, one is the standard API series, which includes Long Thread Casing (LTC) or Short Thread Casing (STC) and partial trapezoidal Threaded joints (Buttress Thread Casing, BTC), the other is a non-standard series of joints, which are collectively referred to as special threaded joints. [0003] Standard API series joints can be divided into two categories: round thread joints and partial trapezoidal thread joints. Among them, round thread joints include long round thread joints and short round thread joints. The advantage of the former is that the processing cost is low, and the disadvantage is that slippage is easy to occur, the tensile strength is not high, and the torsion and compression resistance are insufficient. It is mainly suitable for shal...

AI Technical Summary

Problems solved by technology

[0007] During the drilling process, for ordinary drilling, the universal API standard threaded joint can complete the drilling task, but for the three super gas wells with more severe working conditions (that is, ultra-deep, ultra-high temperature, ultra-high corrosion gas wells) ), the mechanical properties of API standard threaded joints cannot fully meet the working environment of three-super gas wells, especially the escape of high-pressure gas and harmful gases during drilling.

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