A Physics-Informed Monte Carlo Approach for Squeeze Cementing Effectiveness: Eccentricity, Shrinkage, and Pore-Blockage

Abstract Gas leakage in many hydrocarbon wells often occurs due to shrinkage and the formation of microannuli, which are typically located along cement-casing and cement-formation interfaces. These microannuli develop from inconsistencies during the primary cementing process as well as operational issues, ultimately compromising the well’s integrity. Squeeze cementing is a common workover method that entails pumping a thin cement slurry under pressure into these defects to restore integrity. However, despite its frequent use, the success rate of squeeze cementing is relatively low, mainly due to considerable uncertainties regarding the geometry of microannuli, the behavior of the slurries, and the methods used for evaluation. Building on the stochastic model by Trudel and Frigaard [1], which predicts well leakage and was validated with data from British Columbia, Canada, spanning from 2010 to 2019, we established a Monte Carlo method to analyze the injection of yield-stress slurries into irregular microannuli. This method provides probabilistic predictions concerning the outcomes of squeeze cementing and underscores the inherent variability in these operations. In this research, we expand our focus to investigate different operational scenarios, highlighting the crucial role of rheological properties and other factors that affect the success of microannulus repair. By merging probabilistic approaches with in-depth analysis of slurry behavior, we strive to tackle significant uncertainties, enhance the success rates of squeeze cementing operations, and propose practical strategies for restoring zonal isolation and preventing gas migration in hydrocarbon wells.