混注烟道气辅助蒸汽吞吐驱替机理数值模拟研究

摘要

混注烟道气辅助蒸汽吞吐多相多组分渗流机理研究,对深入了解不同于常规蒸汽吞吐渗流物理场的变化和提高热采开发效果都具有重要的意义.通过建立多相多组分渗流数学模型和油藏数值模拟,系统研究了烟道气、蒸汽和原油的相变规律以及多组分体系的变相态渗流特征.结果表明,混注烟道气可有效将油层中蒸汽于度提高至原来的2倍以上,烟道气溶解膨胀作用使原油降粘区域增大,同时烟道气中二氧化碳溶解可有效降低油水界面张力,提高微观驱油效率；混注烟道气辅助蒸汽吞吐周期累积产油量是常规蒸汽吞吐的1.7倍以上,周期日产油量峰值均为常规蒸汽吞吐的1.5倍.烟道气混注参数优化数值模拟结果表明,随着混注比的增加,周期累积产油量呈线性递增的趋势,并且随着烟道气中二氧化碳组分体积含量的增加,周期累积产油量递增的趋势也明显增大.%Study on multi-phase and multi-component seepage mechanism for mixing flue gas assisting steam huff and puff is of great significance for understanding the change of seepage physical field different to conventional steam huff and puff and improving the thermal recovery results. In this paper, multi-phase and multi-component anisotherrnal numerical model is built for reservoir numerical simulation, in order to systematically study the phase change rule of flue gas, steam and crude as well as the variable phase seepage characteristics of multi-component system. The results show that, mixing flue gas injection can increase the steam quality in oil layer effectively. The dissolution and expansion of flue gas significantly extend the crude viscosity reduction range. Meanwhile, C02 dissolution in flue gas can decrease oil-water interfacial tension effectively and increase the microscopic displacement efficiency.