A Numerical Simulation Model For Steam Stimulate Assisted Catalytic Aquathermolysis Of Heavy Oil

At present, many experts concentrate on the research of catalytic aquathermolysis technology of heavy oil. And most research focus on developing catalyst, studying cracking mechanism, evaluating effect of catalyst and taking field test. However, there is no reliable theory for progress parameter design in field application. Study of mathematical simulation is little, and research circle using numerical modeling software is long, which is not benefit on practical application. Against this background, this paper studies the mathematical model of steam stimulation and characters of catalytic cracking. Assume that there is relationship between viscosity-temperature cure after cracking and temperature distribution in formation.The simulator describes the flow of water and heavy oil, and doesn't include gravity and capillary effect. By finite-difference method, establish a two-phase, two-dimensional numerical model for steam stimulate assisted catalytic cracking, which along radial and vertical direction, respectively. Use IMPES method to solve formation pressure and saturation,then solve temperature using implicit expression. Obtain viscosity-temperature curve of regression via laboratory experiment and regression analysis. Use Matlab software to calculate field example and verify the reliability of this model. According to the production characteristic, this model has-6.92% of error. Therefore, it has guiding significance on production prediction and dynamic analysis. Sensitivity analysis indicates that increasing steam injection time and pressure is benefit to increase the radial of heating zone and producing energy, thus improving the effect of catalytic cracking. Increasing steam injection rate can reduce heat losses and improve heat utilization efficiency, which can also improve the effect of catalytic cracking. The lower the oil viscosity, the better the effect of catalytic cracking. But heavy oil with high viscosity has larger radio on improving heavy oil recovery.Relatively speaking, steam soaking time and formation thickness has small effect on it. In conclusion, this model has good behavior on simulating catalytic cracking effect, and is able to provide theoretical direction for field process parameter optimization and production prediction.