Numerical simulation study of the influence of technogenic processes on the Bazhenov formation development

Along with the existing technologies, such as high-pressure air injection, supercritical carbon dioxide injection, and in-situ conversion technology, aimed at developing kerogen-containing reservoirs, e.g., the Bazhenov formation, the super- or subcritical water injection method is considered in the scientific literature. The efficiency of Bazhenov formation development is directly impacted by a number of technogenic in-situ processes, which must be considered in the numerical simulation of the above-mentioned technologies to fully substantiate the optimal scenario of a treatment approach. However, the consideration of in-situ processes in reservoir simulation depends not only on the process itself but also on its contribution to recovery efficiency. Through numerical simulation of two technologies for the Bazhenov formation development – the cyclic subcritical water injection and the cyclic subcritical water with supercritical carbon dioxide injection – the effects of various technogenic processes (such as the thermal conversion of kerogen, the thermal desorption of hydrocarbons, the self-fracking process, the matrix permeability change, the hysteresis of phase relative permeabilities, the wettability change, the clay swelling, and the migration of clay particles) on the cumulative oil production were evaluated in this work. In the course of this study, the aforementioned technogenic processes were arranged in the order of increasing impact on the cumulative oil production. Furthermore, it was shown that the negative effects of the clay swelling and migration can be mitigated due to geochemical processes by adding carbon dioxide to subcritical water. Keywords: Bazhenov formation; supercritical water injection; supercritical carbon dioxide injection; reservoir simulation.