Abstract
Inter-zonal flow of fluids behind cemented casings has plagued the EP industry for years. This has led to the development of many models, but there is still a need for a unified and practical method to design cement sheaths.
Three leakage categories can be distinguished depending on the physical state of the cement when leakage occurs, and this paper focuses on modeling cement sheaths while in solid state (CSSS). It shows first that predictive simulations are not very efficient, even if tremendous improvements have been made the past ten years. Then, a new modeling method (inspired from the Convergence-Confinement Method for designing of tunnel supports) is introduced, the SRC (System Response curve) method, that simplifies CSSS modeling. Using a case of history, where SRC method has been used to help in designing a well, the paper highlights the importance of pore pressure and shrinkage in predictive cement-sheath modeling.
