【摘要】 采用数值模拟的方法,通过考察不同注水模式、注水速率、注水位置、盐度和孔隙度下CO₂的分布特性和溶解行为,系统地分析了注水对CO₂溶解的影响。结果表明,超临界态CO₂呈倒锥形分布于注入井附近的盐水层顶部,并随时间延长缓慢向外扩展。注水虽不明显改变CO₂的分布,但能促进CO₂的溶解,降低超临界态CO₂的量。增大注水速率、靠近盐水层顶部注水、在注CO₂的过程中同时注水均可有效提高CO₂的溶解率。在一定范围内,CO₂的溶解量随盐水盐度降低而提高,但几乎不随岩石孔隙度变化。研究表明,通过优化注水条件可以显著促进CO₂的溶解封存。更多还原

【Abstract】 This paper is to devote itself to a simulation study of the impact of injecting water into the saline aquifer on the supercritical dissolution of CO₂ based on a self-developed program,that is,the so-called SoFaR_PM.For the purpose,we have also developed a two-dimensional cylindrical saline aquifer model 100 m thick with its radius beinglOO km around.We have also adopted the Newton-Raphson method to solve the equations of the flow and transfer of CO₂ in the said saline aquifers.While taking into consideration an injection rate of water at a rate of 10 kg/s during a period of 30 years for CO₂,it is necessary to make the injection rate and duration varied in a range of 3-50 kg/s and 30-70 years.The simulation results we have gained indicate that the injected supercritical gas of CO₂ gathered at the top of the saline aquifer should crop up in a shape of an inverted cone.At the same time,it can also be made to expand radially with time and the increased degree of CO₂ dissolution.However,the injection of water during or after the CO₂ injection should not be able to change the CO₂ distribution rate obviously,but rather enhance its dissolution significantly.What is more,as compared with the case of water injection following the CO₂ injection,simultaneous injection of water and CO₂are supposed to₁ ead to pronounce a great more of CO₂ dissolution.Thus,needless to say,a higher rate of water injection,plus a shorter distance of the water injection point to the top of the saline aquifers,may surely result in more CO₂ dissolution.Thus,it can also be concluded that lower salinity of the saline injection is expected to be more beneficial for promoting higher amount of CO₂ dissolution.In contrast,changing the rock porosity can hardly influence the CO₂ dissolution.Therefore,the simulation results of this paper clearly shows that water injection can greatly help to enhance the CO₂ dissolution in the saline aquifers,which helps to make the results of the present study a guide to the development of CO₂ storage technology更多还原