YUE Qianbei,LI Hui,XU Pingwen,et al. Strength analysis of multisage fracturing string and study on its influence law[J]. Journal of Mechanical Strength,2026,48(1):48-55.
YUE Qianbei,LI Hui,XU Pingwen,et al. Strength analysis of multisage fracturing string and study on its influence law[J]. Journal of Mechanical Strength,2026,48(1):48-55. DOI: 10.16579/j.issn.1001.9669.2026.01.006.
Strength analysis of multisage fracturing string and study on its influence law
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
2
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
2
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.
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