A Collapse Strength Model for a 7” Crescent-Worn Casing Connection Considering Sealing Integrity

Collapse failure under external pressure is one of the common forms casing. Much research has been performed on casing body, but few threaded connection, in view general belief that connection a thicker wall and larger collapse strength than body. However, pressure, sealing capacity worn will decrease due to deformation structure, so influence ability should be considered determine In this paper, we established three-dimensional finite element model 7” crescent-worn calculated different wear depths. Meanwhile, stress distribution characteristics surface were obtained performance was analyzed. The results showed when rate exceeds certain value, based integrity lower Based these, for considering developed safety evaluation method string proposed.