Analysis of expansion performance and parameter sensitivity of solid expandable tubular with thread joint. (February 2023)

• Record Type: Journal Article
• Authors: Shi, Changshuai; Liu, Yi; Zhu, Xiaohua; Cheng, Feilong
• Is Part Of: Engineering failure analysis. Volume 144(2023)
• Publication Date: 2023-02
• Subjects: Solid expandable tubular thread joint -- Mechanical model analysis -- Parametric sensitivity analysis -- Finite element analysis; System failures (Engineering) -- Periodicals; Fracture mechanics -- Periodicals; Reliability (Engineering) -- Periodicals; Pannes -- Périodiques; Rupture, Mécanique de la -- Périodiques; Fiabilité -- Périodiques; Fracture mechanics; Reliability (Engineering); System failures (Engineering); Periodicals; Electronic journals; 620.112
• DOI: 10.1016/j.engfailanal.2022.106987
• Languages: English
• ISSNs: 1350-6307

Abstract

Highlights: Rectangular thread and trapezoidal thread, as symmetrical tooth thread, are severely affected in the expansion process, and the tightness of the thread joint is difficult to ensure. It is not recommended to be used as solid expandable tubular thread in casing management. The joint with special trapezoidal thread structure has better meshing and structural integrity, the distribution of residual stress and contact pressure in the joint is high at both ends and low in the middle. Rectangular thread and trapezoidal thread are not suitable for solid expandable tubular thread joint connection, and it is difficult to ensure the connection strength and tightness after expansion. On this basis, a kind of special deviatorical trapezoid thread is proposed, and the conclusion is obtained through the experiment and numerical simulation, the optimal load bearing Angle is −6° to −12°, and the optimal guide surface is 7° to 13°, in this range, the residual stress of the threaded joint is small, and the meshing efficiency increases significantly. The best tooth depth is 1.37 mm to 1.57 mm, which is the highest mesh efficiency. The optimal tooth pitch is 5.08 mm, and the residual stress decreases significantly with the increase of tooth spacing. The optimum taper is 1:16, the increase of taper significantly increases the contact pressure of the first turn thread after the joint is swollen. Abstract: During the expansion process of the threaded joint of the solid expandable tubular (SET), the thread meshing performance and sealing performance will deteriorate, which seriously hinders the development and application of the SET. In this paper, established the force analysis model of different threads in the bulging process and analysis the finite element model of thread. The meshing performance of φ108 mm × 7 mm SET joints made of 20G steel with three types of thread expansion is analyzed. The most suitable parameter range was obtained by optimizing the five thread parameters such as bearing surface angle, guide surface angle, taper, tooth depth and tooth pitch. The results show that the rectangular and trapezoidal threads are deformed seriously during expansion, and the connection of rectangular and trapezoidal threads is easy to cause the seal failure of the SET system; The effects of various thread parameters on the Mises stress and contact pressure distribution were analyzed. It was found that the Mises stress of the first turn of the special skew trapezoidal thread was the highest, and the Mises stress distribution was high at two ends and low at the middle, with the maximum difference of 160 MPa and the contact pressure distribution was high at two ends and low at the middle, with the maximum difference of 200 MPa. The research results provide technical support for obtaining the SET thread with good meshing performance after expansion.