INFLUENCE OF THE THERMOPHYSICAL PROPERTIES OF THE RESERVOIR AND FLUID ON THE TECHNOLOGICAL PARAMETERS OF THE CYCLIC STEAM STIMULATION

At present, hydrodynamic models do not allow simulation of local eff ects of thermal fi elds with suffi cient accuracy, and integral models do not take into account the steam mass fraction in the heat transfer fl uid. The purpose of this work is the analysis of the infl uence of thermophysical parameters of the reservoir and fl uid on the optimal times of stages of cyclic steam stimulation of the reservoir and of additional maximum cumulative oil recovery. For the fi rst time, an integral mode has been developed for cyclic steam stimulation, accounting for the steam mass fraction in the heat transfer fl uid and the equation of state for water. The model is based on the use of heat balance relationships for each type of cyclic steam stimulation. The steam temperature in the production interval, the initial reservoir temperature, and the heat fl ux are determined by the data from short-term dynamic temperature studies. The oil fl ow rate is determined by the Dupuis formula for a zone-heterogeneous reservoir. Optimal times for cyclic steam stimulation stages and the maximum cumulative oil recovery have been determined. It is shown that the optimal time of the heat transfer fl uid injection to the reservoir and the time of steam soak for the well increase with increase in the reservoir thickness, the heat transfer fl uid fl ow rate, and the steam mass fraction in it. Limits have been identifi ed to the applicability of cyclic steam stimulation in terms of the heat transfer fl uid fl ow rate.
At present, hydrodynamic models do not allow simulation of local eff ects of thermal fi elds with suffi cient accuracy, and integral models do not take into account the steam mass fraction in the heat transfer fl uid. The purpose of this work is the analysis of the infl uence of thermophysical parameters of the reservoir and fl uid on the optimal times of stages of cyclic steam stimulation of the reservoir and of additional maximum cumulative oil recovery. For the fi rst time, an integral mode has been developed for cyclic steam stimulation, accounting for the steam mass fraction in the heat transfer fl uid and the equation of state for water. The model is based on the use of heat balance relationships for each type of cyclic steam stimulation. The steam temperature in the production interval, the initial reservoir temperature, and the heat fl ux are determined by the data from short-term dynamic temperature studies. The oil fl ow rate is determined by the Dupuis formula for a zone-heterogeneous reservoir. Optimal times for cyclic steam stimulation stages and the maximum cumulative oil recovery have been determined. It is shown that the optimal time of the heat transfer fl uid injection to the reservoir and the time of steam soak for the well increase with increase in the reservoir thickness, the heat transfer fl uid fl ow rate, and the steam mass fraction in it. Limits have been identifi ed to the applicability of cyclic steam stimulation in terms of the heat transfer fl uid fl ow rate.
Author:  A. Ya. Gil′manov, A. P. Shevelev, P. S. Lagunov, P. N. Gulyaev, A. S. Petukhov, P. A. Lyutoev
Keywords:  cyclic steam stimulation, heat balance, sensitivity analysis, steam injection rate, optimal time of the heat transfer fl uid injection, additional cumulative oil recovery, steam condensation
Page:  1311