X-ray radiographic imaging of unsteady flows in porous media

X-ray radiography is used to sample the moving phase interface in a sequence of water–air and water–oil displacements. A bench-top X-ray CT scanner is used with a still sample continuously flooded with a positive-displacement type pump. A method is proposed to compute two-dimensional instantaneous saturation distributions from the radiographic sequence. Exploitation of the saturation profiles to drive a history-match procedure is demonstrated. This work shows that using simple radiographies of multiphase flows provides a real-time and low-cost method for tracking flooding processes through rock core samples and obtaining relative permeabilities thereof. Most important, due to the much higher frame rate attainable by taking radiographic images, compared to traditional X-ray CT scanning, flows with higher injection rates can be followed.