Radiotracer assisted visualization and CFD modelling of multiphase fluid flow in porous media

The intension of the present project has been to study some basic phenomena of fluid flow in porous media for enhanced oil recovery purposes. One goal has been to study the use of both passive water tracers and water/oil partitioning tracers in a heterogeneous reservoir to measure remaining oil saturation. These studies have been carried out by targeted laboratory experiments utilizing radioactive tracers and nuclear detection techniques. Conventional core flooding experiments have been conducted to qualify tracers for this purpose. Water has been labelled with tritiated water (HTO), 131I- and 57Co(CN)63-. Two partitioning radiotracers have been qualified at simulated reservoir conditions (reservoir-like rock, pH, temperature and pressure). They will here be named Part 1 and Part 2. Construction and fabrication of a mini-reservoir has been implemented in which tracers can be injected in injection wells, move in the pore space through the reservoir rock and then be produced in production wells. In sequential experiments this reservoir has been prepared to full water saturation, to full oil saturation at residual water saturation and to residual oil saturation after water flooding. The movement of tracers and the space differential fluid saturations in the reservoir has been recorded by gamma camera detection and by sampling of produced fluids in the various production wells followed by detection by gamma spectroscopy or liquid scintillation counting. (author)