Area of Reservoir Heating during Steam Cyclic Treatment of Oil Wells

To develop difficult-to-recover high-viscosity oils, thermal well treatment methods are applied ensuring the reduction of oil viscosity and the increase of oil recovery, thus decreasing the time of development. Among such methods is steam cyclic well treatment. Steam cyclic method of treatment involves three consecutive stages forming a cycle that can be repeated many times: steam injection stage, steam treatment stage, and oil production stage. The displacement of fluid from reservoir by steam occurs in three stages. The first stage is the formation of the area of the so-called “steam plateau”, which is the region of saturated vapor and water filtration at saturation temperature and reservoir pressure. In this case, the condensation of steam with the heat release takes place, which is sent to reservoir, increasing the temperature in it. The second stage is the displacement of the liquid from reservoir by hot water formed as a result of steam condensation. In the third stage of heat treatment, a stationary temperature field in the reservoir is formed. The whole process of steam cycling is affected by several factors, while the area of reservoir heating is difficult to determine. The integral method proposed in this paper makes it possible to make a preliminary assessment of the heating area of oil reservoir.