Carbonated water injection (CWI) for improved oil recovery and carbon storage in high-salinity carbonate reservoir

Abstract

Abstract Carbonated water injection (CWI) is a promising alternative of conventional CO2 flooding which requires smaller amounts of CO2. Currently, most the CWI research focuses on the micromodel and sandstones, but a comprehensive study of the application of CWI in carbonate reservoir is missing in the literature, especially when the reservoir fluid has high salinity. A feasibility study is carried out in this work to design a workflow to thoroughly understand CWI mechanisms for improved oil recovery (IOR) in such reservoirs with the example of Lansing Kansas City (LKC) Group carbonate reservoirs of Kansas and the composition of the produced water. We literature survey and propose approaches for measurement and model of CO2 solubility in brine, so as to establish the apparatus for measuring CO2 solubility in brine to verify or modify existing models of high-salinity solubility. Also, we propose the approach to measure the contact angle when processes of dynamic wettability alternation and substrate dissolution in different minerals and natural carbonate rock occur. Further, we examine and predict outcomes of the micromodel experiment for exploring mechanisms contributing to additional oil recovery, contact angle measurement of carbonated-brine/oil/rock for observing rock wettability alternation and calcite dissolution, and core flooding experiment for observing oil recovery performance as a tertiary method or secondary method.