The research presents a standard method for studying the porous medium of natural core samples using X-ray microtomography. Additionally, it introduces a proprietary technique based on the mathematical processing of the obtained images, which refines the interpretation of the data. In this way, the authors address the following tasks: to determine the porosity and permeability coefficients of the samples, identify the internal structure of the rock, and predict residual oil saturation. For example, the traditional method of assessing absolute porosity yields a result of 16%, compared to 25% obtained through the proprietary technique. This increase is achieved by accounting for blur (i.e., the distribution of probability brightness of image points, which are classically assigned to the skeleton, void space, or a combination of void space and skeleton). Consequently, the solution based on the combination of standard and original imaging technologies makes it possible to identify and evaluate the structure of the reservoir-filtration space, the residual oil saturation coefficient, and the impact of secondary processes on initial porosity. This approach is classified as a direct research method, with a resolution ranging from 0.5 μm to 27 μm, making it possible to study the internal structure of objects in detail, in volume, without compromising the integrity of the samples, whether in weakly cemented or lithified rocks. In this research, the authors do not review existing tomographic research methods but rather examine the sources of errors in the imaging and processing technology to achieve a more substantiated and higher-quality result.