Development of reacted channel during flow of CO2 rich water along a cement fracture

Lab scale experiments were performed to characterize how coupling between reaction and flow affect time-dependent flux of CO2-rich water along leaky wells. The core flow system applies confining stress to a cement core with a single tensile fracture while CO2-rich water is injected at constant rate and elevated pore pressure. Results show no significant variation in pressure differential, despite the development of a texturally distinct calcium depleted channel along the fracture surfaces which is bounded by thin rims of precipitation. Silicon rich material remains in the channel and prevents wormhole development and large increases in aperture. Implications for time-dependent CO2 leakage are that even with high fluid flux, the leak does not get appreciably worse. (C) 2013 The Authors. Published by Elsevier Ltd.