Long-Term Integrity of Well Cements for CO2-Storage Through Self-Healing Capabilities - Test Development

Abstract

Abstract Self-healing wellbore sealants, that (chemically) react with leaking fluids such that when leakage pathways form, they are sealed rather than widened, can be a key technology for ensuring long-term seal integrity in CCS and other geological storage applications. Developing such sealants requires representative and reproducible testing methods, to assess how a leakage pathway through a selected sealant material evolves when exposed to a flow of leaking fluid under in-situ conditions. Here, we will present novel experiments, in which a reproducible simulated leakage pathway through a sealant sample is exposed to a constant flow of supercritical CO2. During exposure, up- and downstream fluid pressures are monitored to assess changes in permeability. Microstructural and mineralogical changes are assessed afterwards, using SEM with EDS.