Integrated Effect of Fines Migration and Mineral Reactions during Flow in Porous Media

Fines migration can cause permeability damage during water injection into aquifers or petroleum reservoirs. However, previous fines migration studies did not consider mineral reactions. This thesis investigates whether mineral reactions can cause fines migration, and if so, how this would influence permeability. Three different processes are investigated: 1) water injection into sandstone rocks, 2) water injection into carbonate rocks, and 3) CO2-saturated water injection into sandstone rocks. Chapter 2 presents two sets of single-phase water injection experiments conducted on Berea sandstones When NaCl brine is used, the percentage of permeability decrease is found to be 99% at 25°C, 90% at 50°C, and 40% at 70°C.The lower permeability decrease at high temperature is found to be accompanied by a smaller concentration of produced fines. With CaCl2 brine, a 7% permeability decrease is observed at 25°C, whereas a 20% permeability increase is observed at 50°C. The observed fines concentration and increase in Ca2+ ion production is found to be lower than with NaCl brine, which is attributed to ion exchange between Na+ and Ca2+ with NaCl brine. Temperature affects both (1) permeability increase due to pore enlargement caused by mineral reactions, and (2) permeability decrease due to fines migration. Chapter 3 presents single-phase water injection experiments performed on carbonate rocks (Edwards Brown and Indiana limestone). The increase in the pH of the produced water suggests mineral reactions, which is supported by an increase in the ionic concentration of the produced water. The percentage of permeability decrease is found to be 99.9% for Edwards Brown, whereas 68% for Indiana limestone. Results demonstrate that mineral reactions cause mobilization of fines and rock grains, leading to significant permeability decrease. Chapter 4 presents an experimental and modelling study to analyze the effect of fines migration and mineral reactions during CO2 sequestration into sandstones. The results suggest that two competitive phenomena occur due to carbonate mineral dissolution during CO2-saturated water injection, (1) increased porosity that is responsible for the increase in permeability and (2) fines migration that results in permeability decrease. Dissolution of intergranular cement results in fines, some of which subsequently cause pore blockage and permeability decrease