Author(s)

Na Xiao¹, Shi Li², Meiqin Lin³

¹Key Laboratory of Drilling and Production Engineering for Oil and Gas, College of Petroleum Engineering, Yangtze University, Wuhan, China.
²Research Institute of Petroleum Exploration & Development, Beijing, China.
³Enhanced Oil Recovery Research Center, China University of Petroleum, Beijing, China.

Injecting CO₂ into underground reservoir to displace oil is a viable means of reducing greenhouse gas emission to the atmosphere and enhancing oil recovery. To evaluate the effect of CO₂-water-rock interactions on the characteristics of carbonate reservoir at high pressure, the mineralogy of calcite, the ion concentration in the reacted solution, the surface texture of calcite, the permeability of calcite after reacted with injected CO₂ and deionized water was investigated by X-ray diffraction (XRD), inductive coupled plasma-atomic emission spectrometry (ICP-AES), scanning electronic microscope (SEM), and sand-packed model at pressure of 5.0 MPa. The results show that the mineral dissolution of calcite would occur when interacting with injected CO₂ and water. The mineral dissolution of calcite caused the change of surface texture of calcite and increase in Ca²⁺, HCO^-₃ ion concentration in the solution. With the increase of CO₂ pressure, the surface dissolution of calcite appeared more obvious. With the increase of reaction temperature, the surface dissolution of calcite also appeared more obvious and Ca²⁺, HCO^-₃ ion concentration in the solution increased first, then decreased. The mineral dissolution of calcite caused the improvement in water permeability of calcite/quartzsand-packed model.

CO₂ Flooding, CO₂-Water-Rock Interaction, Calcite, Dissolution, Surfacetexture, Permeability

Xiao, N. , Li, S. and Lin, M. (2017) Experimental Investigation of CO₂-Water-Rock Interactions during CO₂ Flooding in Carbonate Reservoir. Open Journal of Yangtze Oil and Gas, 2, 108-124. doi: 10.4236/ojogas.2017.22008.