INFLUENCE OF CONVECTIVE PROCESSES ON TECHNOLOGICAL PARAMETERS OF CYCLIC STEAM STIMULATION OF OIL RESERVOIRS

The focus of the article is simulating the technology of cyclic steam stimulation of producers for heavy-oil fields and analyzing the influence of convective processes on basic technological parameters. With the model taking account of gravitational segregation and convective heat fluxes of the steam, technological indices of the process have been determined, including the time of steam injection and the time of steam-thermal condensation. The process of cyclic steam stimulation is described by the integral model which is based on heat balance. The rotation of the coordinate system makes it possible to consider quasi-one-dimensional solutions. A comparison of model and field data on the Sho-Vel-Tum field was made, which has shown a satisfactory agreement. In the course of numerical experiment, it has been shown that the expectation time for the full condensation of the steam, which leads to the well shutdown, is unjustifiably overstated at this field. It has been shown that account taken of convective flows of the steam enables one to raise the accuracy of prediction of steam-injection intervals. Long-term preservation of the effect of cyclic steam stimulation has been established for cumulative additional oil recovery as applied to the Sho-Vel-Tum field.