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Experimental Observation of Channel Propagation and Dissolution Forecasting on Calcite Samples at Different Effective Pr
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 80th EAGE Conference and Exhibition 2018, Jun 2018, Volume 2018, p.1 - 5
Abstract
Acidity of percolating water is a key control in the dissolution of carbonates resulting in the creation of preferential flow paths. The mechanisms behind their development are important for a number of subsurface issues, e.g. carbon sequestration, groundwater resource competition, geo-energy applications including geothermal energy and energy storage applications, as well as EOR. This project aims to experimentally and numerically investigate the mechanically and chemically induced poropermeability changes that occur in carbonate rock samples by using a slightly acidic and purified seawater as an injection fluid in core flood experiments under typical geo-reservoir conditions (~5km depth) of pressure, temperature and representative geochemistry. The experimental plan involves 38mm diameter cores confined at reservoir conditions (50MPa). The first set of experiments focus on the coupling between the applied effective stress and the volume of fluid injected through a rock. Initial results suggest a potential link between injection rate and stress corrosion on carbonate dissolution. Weighting the influence of each of these processes on matrix stimulation requires more work, but the early results show a clear relationship between pore volume injection (related to rock structure and the injection rate) and preferential channel formation amongst the rocks.