Engineering Physics Annotation << Back CRITICAL DIFFERENCE IN THE MATHEMATICAL MODELS OF THE PRESSURE FIELD AT INSTANT TAKING FROM THE FORMATION AND (OR) WELL A.I. FILIPPOV, M.A. ZELENOVA Mathematical models of pressure fields in an oil-bearing reservoir and a well are presented for short-term withdrawal from the reservoir and (or) well, taking into account the infl uence of pumping equipment. The well influence was taken into account by using the boundary condition in the form of a differential equation that takes into account the change in the level of the liquid column in the well and the inflow from the formation. This removes the problem under consideration from the category of classical problems of mathematical physics. The case under consideration corresponds to turning on the pump for a short period of time. This mode is widely used in the study of wells and reservoirs to determine the production potential of hydrocarbons, especially in exploration wells. The approach used in the work allows one to obtain expressions for the case when the time for pumping fl uid out of the reservoir or well is much less than the time for establishing equilibrium in the "well-reservoir" system. The short-term selection was taken into account by using the apparatus of the theory of generalized functions. Expressions are presented that allow calculating the space-time distributions of pressure in the reservoir and in the well for both cases under consideration. On the basis of computational experiments, it was found that at the initial moment of time, the minimum pressure values are reached. It is shown that to ensure short-term production from the formation, signifi cantly larger pressure drops are required than to create the same pressure from the well. The pressure drop ratio for the considered cases is tens of thousands, which indicates a catastrophic difference between the developed models. Keywords: filtration, pressure field, "instantaneous" selection, piezoconductivity equation. DOI: 10.25791/infizik.11.2021.1235 Pp. 16-21.