Research on cohesive failure behavior and parameter sensitivity of rubber – SET under cohesive zone model. (October 2022)

• Record Type: Journal Article
• Authors: Shi, Changshuai; Wang, Ao; Zhu, Xiaohua; cheng, Feilong
• Is Part Of: Engineering failure analysis. Volume 140(2022)
• Publication Date: 2022-10
• Subjects: Cohesive zone model -- Solid expandable tubular -- Rubber -- Cohesive failure; 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.2022.106492
• Languages: English
• ISSNs: 1350-6307

Abstract

Highlights: The cohesive zone model is introduced to research the cohesive failure behavior of SET rubber. The friction coefficient of the casing - rubber - SET system and the optimum length and compression of rubber are suggested. The influence of cohesive parameters on cohesive failure behavior of SET rubber is researched. The influence of cohesive parameters on cohesive failure behavior of SET rubber is researched. Abstract: Solid expandable tubular (SET) technology is widely used in oil field. The cohesive failure of rubber reduces the suspension and sealing capacity of SET. Based on cohesive failure behavior between rubber and SET and morphological characteristics of rubber after expansion experiment. The cohesive zone model was introduced to describe cohesive behavior. The coupled three-dimensional finite element model of casing - rubber - SET was established. The effects of sensitive factors such as friction factors, rubber compression, rubber length, stiffness, damage initiation strength and fracture energy on cohesive failure behavior of SET rubber were researched. The results show that (1) In order to ensure that driving force in expansion process is small and meet the requirements of suspension force and sealing pressure after expansion. The friction coefficient of casing - rubber - SET system should be about 0.15. (2) On the premise of no cohesive failure occurs, the suspension force and sealing performance of rubber can be effectively improved by increasing theoretical compression and length of rubber. The optimum theoretical compression of rubber is about 50% of rubber thickness. The length of rubber should not exceed 60 mm. (3) Reducing stiffness and increasing damage initial strength of bonding material can reduce the risk of cohesive interface failure. The normal stiffness should not be greater than 5.4 N/m 3 and the tangential stiffness should not be greater than 6.3 N/m 3 . The normal ultimate tensile stress should not be less than 9.6 MPa and the transverse shear stress strength should not be less than 9.7 MPa. It is not significant to increase bonding property of rubber by increasing fracture energy. The research results provide theoretical guidance for the structural design and bonding process parameters of SET rubber.