Junyan Liu¹, Ju Liu¹, Yan Wang¹, Shuang Liu¹, Qiao Wang¹, Yihe Du^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.1, pp. 205-218, 2024, DOI:10.32604/fdmp.2023.030645

Abstract The variation of the principal stress of formations with the working and geo-mechanical conditions can trigger wellbore instabilities and adversely affect the well completion. A finite element model, based on the theory of poro-elasticity and the Mohr-Coulomb rock damage criterion, is used here to analyze such a risk. The changes in wellbore stability before and after reservoir acidification are simulated for different pressure differences. The results indicate that the risk of wellbore instability grows with an increase in the production-pressure difference regardless of whether acidification is completed or not; the same is true for the instability area. After acidizing, the… More >

Xuesong Xing¹, Renjun Xie¹, Yi Wu¹, Zhiqiang Wu¹, Huanqiang Yang^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.6, pp. 1719-1735, 2022, DOI:10.32604/fdmp.2022.019799

Abstract

The bonding quality of the cement sheath interface decreases during well completion because of the change in the casing pressure. To explore the root cause of such phenomena, experiments on the mechanical properties and interface bonding strength of a cement sheath have been carried out taking the LS25-1 high-temperature and high-pressure (HTHP) gas field as an example. Moreover, a constitutive model of the cement sheath has been defined and verified both by means of a full-scale HTHP cement sheath sealing integrity evaluation experiment and three-dimensional finite element simulations. The results show that the low initial cementing surface strength is the… More >