4D X-ray computed tomography is a temporary 3D image of dynamic processes, where "time" is considered the 4th dimension. This subject appeared and began to develop in the late 1990s - early 2000 in medicine, where it became a solution of the object segmentation problem at various stages of cyclic movements in a person’s body (for example, breathing or heartbeat). The use of 4D-microCT for the study of filtration processes in oil production (in particular, with the physicochemical methods of enhanced oil recovery (EOR)) can provide not only new information about the physical features of these processes but also develop new methods for their testing and modelling.
4D-tomography can be divided into 2 varieties. In the first, the processes are suspended during the tomography. The result of such research resembles an animation, where the individual stages of the dynamic process are displayed. The advantage of this approach is the high quality of the resulting tomography. In the second - the processes occur continuously. This requires a fast, continuous sample shooting and a slow dynamic process concerning the shooting time. The advantage of this method in the continuous study of the dynamic process. However, this method inevitably leads to a decrease in the quality of tomography, the appearance of noise and artefacts.
In our work, we consider the differences in the application of both techniques in the study of pore-scale oil displacement processes. In particular, the work demonstrates significant differences in the shape and connectivity of the phases during the staged and dynamic microCT. The application of 4D- microtomography at the pore scale has a great potential for experimental studies in the oil industry and verification of digital rock physics models.
This work was funded by the subsidy allocated to Kazan Federal University for the state assignment in the sphere of scientific activities (Project No. 0671-2020-0048).
