Reservoir Evaluation and Development ›› 2021, Vol. 11 ›› Issue (2): 223-229.doi: 10.13809/j.cnki.cn32-1825/te.2021.02.012

• Shale Gas Development • Previous Articles     Next Articles

Cause analysis of casing deformation in fracturing of horizontal wells in Weirong deep shale gas field

QIAO Zhiguo(),YE Cuilian   

  1. Research Institute of Engineering Technology, Sinopec Southwest China Oil and Gas Company, Deyang, Sichuan 618000, China
  • Received:2020-10-27 Online:2021-04-26 Published:2021-04-30

Abstract:

Casing deformation occurs frequently during the development of the Weirong Shale Gas Field in the Sichuan Basin. In order to solve this problem, analysis on load and deformation degree of three casing deformation has been carried out by finite element method to discuss the deformation type. Meanwhile, by means of theoretical analysis, finite element simulation and equivalent test evaluation, the quantitative analysis is carried out on the parameters such as the overall angle change rate, cementing quality, wellbore temperature-pressure change and instantaneous stop pump. The influence of different engineering factors on casing strength weakening shows that the engineering factors are not the main factors of casing deformation. According to the analysis of comprehensive factors in the transformation process such as formation anisotropy, wellbore temperature-pressure coupling and reservoir lithologic interface, it is considered that the casing strength decreases under engineering conditions, while in the process of fracturing, the slip of weak strata or the non-uniform compression load of reservoir on casing leads to casing stress concentration and deformation. The relevant understanding provides a reference for the formulation of casing deformation prevention and control measures of Weirong Shale Gas Field.

Key words: shale gas, casing deformation, cementing quality, volume fracturing, shear deformation, extrusion deformation

CLC Number: 

  • TE37