Single-hook screw thread and end plane metal self-sealing expansion sleeve pipe

Abstract

Disclosed is an expansion casing with single hook shape screw thread and end surface metal self-sealing, which is an expansion casing applied to petroleum oil gas well engineering. The expansion casing is characterized in that the external thread and the internal thread are provided with single hook shape screw threads, and the single hook shape screw threads match with each other to form thread hook surface metal sealing. The top of the external thread and the root of the internal thread are provided with cylindrical metal sealing surfaces, and the metal sealing surfaces match with each other to form cylindrical metal sealing. the cylindrical metal sealing surface of the internal thread is provided with an annular sealing groove and a rubber sealing ring which plays the sealing function.The expansion casing has the effects that the external thread and the internal thread has negative angle hook shape internal and external threads which are tightly engaged and even contact stress distribution, thereby having stronger tensile strength. The single hook shape threads, the metal sealing surface and the rubber sealing ring play the sealing function together. The expansion casing has sealing integrity, expansion joint strength evenness, and low machining cost.

Description

technical field [0001] The invention relates to casings in oil and gas well engineering, in particular to an expansion casing, which relates to a threaded structure for joint connection of expansion casings. The single-hook thread and end metal self-sealing expansion casing is suitable for expansion without couplings Casing connection. Background technique [0002] At present, the expansion casing technology will become one of the technologies that play a key role in the oil drilling industry in the 21st century. It is mainly used in many fields such as drilling, plugging complex layers, liner hanger and casing repair. The ability to form complex formations, improve drilling efficiency, and reduce drilling costs. Expandable casing technology is a new drilling technology that expands the pipe string radially to the plastic deformation area in the wellbore to achieve the purpose of "saving" the borehole diameter. Enventure company took the lead in the research of this techn...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a single hook-shaped thread and metal self-sealing expansion sleeve on the end face, which overcomes the disadvantage that the conventional thread cannot be directly processed on the expansion sleeve with no collar and thin wall thickness, based on the highly nonlinear elastoplasticity The finite element simulation technology of the thread contact and the contact between the nonlinear hyperelastic rubber and the metal surface provides a metal self-sealing expansion sleeve thread with a single hook end face that has good sealing performance and uniform expansion strength for the expansion sleeve. connector

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