The pipe/cement/pipe system, critical to oil and gas well construction, ensures structural integrity under various loading conditions. Imperfections can reduce the system’s collapse-strength enhancement significantly. This paper examines the effects of cement voids and microannuli on the collapse resistance of the pipe/cement/pipe system, with void angles ranging from 0° (no voids) to 70°. The objective is to provide comprehensive technical understanding of these factors, offering valuable insights for risk assessment of the structural integrity of the pipe/cement/pipe system under external pressure alone or with annular pressure buildup between the inner and outer casings.
Nonlinear Finite-Element Analysis (FEA) Modeling of Pipe/Cement/Pipe Collapse
A nonlinear finite-element model, incorporating material nonlinearity (elastic-plastic constitutive model with strain hardening) and geometric nonlinearity (finite deformation) was developed and analyzed. Parametric inputs and scripting were employed to streamline the extensive modeling and simulation efforts.
