Strength analysis of multisage fracturing string and study on its influence law
YUE Qianbei
LI Hui
XU Pingwen
WANG Gang
XU Yanlu
JING Boxiang
LIU Jubao
Abstract：[Objective]Aiming at the string strength failure problem induced by the packer system during multi-stage fracturing,the investigation on the mechanical behavior of the string and the influence law of strength was carried out to ensure the safety of fracturing operations and the structural reliability of the string.[Methods]Firstly,based on the working characteristics of multi-stage packers,a mechanical model of the fracturing string system was established,and the governing equations under the two working conditions of setting and fracturing were derived.Secondly,the finite element method was adopted,and the packer displacement was taken as the initial boundary condition of the fracturing working condition.Then,the non-deterministic boundary conditions of packer sliding and fixing were considered,and a numerical calculation method for the multi-stage fracturing string system was constructed.Finally,calculation and analysis were carried out through field well cases.[Results]The analysis results showed that with the increase of fracturing stages,the wellhead axial force and equivalent stress increased significantly,and the safety factor decreased gradually;the fracturing fluid flow rate,wellhead pressure and proppant concentration all had significant effects on the string strength;the increase of any parameter would lead to the increase of axial force and the decrease of safety factor,thereby aggravating the risk of string strength failure.The research results provided a basis for the strength design and safety evaluation of multi-stage fracturing strings.
Keywords：Finite element methodPipe elementMulti-stage fracturingStrength of tubular column
Publication Date：2026-01-31
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)
Pages：8( 48-55 )