Special Oil & Gas Reservoirs ›› 2024, Vol. 31 ›› Issue (1): 152-158.DOI: 10.3969/j.issn.1006-6535.2024.01.020

• Drilling & Production Engineering • Previous Articles     Next Articles

Stress Analysis and Influencing Factors of Perforation in Heavy-Oil Thermal Recovery Wells

Liang Jiangling1, Yang Hong1, Su Hongyi1, Lin Tiejun2, Zhao Chaoyang2, Dan Han2   

  1. 1. PetroChina Xinjiang Oilfield Company, Karamay, Xinjiang 834000, China;
    2. National Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 615000, China
  • Received:2023-03-20 Revised:2023-12-17 Online:2024-02-25 Published:2024-04-18

Abstract: Aiming at the problems of frequent damage and fracture of perforated casing during the production process of thermal recovery wells, based on the theory of elasticity-plasticity and thermodynamics, a finite element thermodynamic coupling model of perforated casing during the process of steam injection-stewing-production was established by using finite element method to research the stress distribution characteristics of the perforated casing in each stage, and analyze the strength influence rule of the perforated casing under different parameters of perforated casing. The study shows that the obvious stress concentration occurs at the location of the injection hole boreholes during the production process. The casing stress could reach up to 498.16 MPa in the early stage, and the plastic failure occurs gradually under the joint action of the temperature difference and the internal and external pressure difference. The casing plastic failure is the most serious once the injection and production operation is completed. The influence of the perforation density on the value of Mises stress decreases with the increase of the perforation phasing degree, and the maximum perforation stress is inversely related to the perforation phasing degree. This study is of great significance to prolong the service life of perforated casing in heavy-oil thermal recovery wells and to ensure normal production operation.

Key words: heavy-oil thermal recovery, casing damage, perforation, casing strength, stress con-centration

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