Optimization of technological parameters for cyclic steam stimulation of oil reservoirs

Abstract

Depletion of oil reserves leads to need to develop unconventional and hard-to-recover reserves, including high-viscosity oil fields. An effective way to do this is to use thermal enhanced oil recovery methods. Existing models do not consider the actual displacement of the heating front with convective flows. Therefore, the actual tasks are to model the physical processes occurring in the reservoir and to optimize the technological parameters of the development during cyclic steam stimulation. This article is a continuation of earlier research and offers to consider a different version of movement of boundary of heating front. Clarification of the development of thermal field in reservoir is associated with setting the shape of boundary considering gravitational forces, in contrast to the previously proposed model, where the assumption of the frontal propagation of the thermal front is accepted. The aims of the article are to determine the production rate for cyclic steam stimulation with described geometry; calculation steam injection time using real data, optimization of production. The research methodology is based on the use of a system of conservation laws. The main equations are solved analytically, and the flow rate is calculated using Newton’s iterative method. Thus, this article offers the first integrated physical-mathematical model of cyclic steam stimulation, considering the presence of convective and gravitational forces in the formation of heated zone profile. Problem of production optimization is solved using real data. The characteristic times are consistent with the real data. These calculations help to choose the most rational development strategy.