摘要
采用巨正则蒙特卡洛方法,对CO_2/CH_4混合物在页岩储层黏土矿物—伊利石孔隙结构中的吸附特性进行研究。模拟结果表明,随着地层深度的增加,在同一CO_2注入比例下,CH_4的吸附量呈现先增加、后趋于平缓的趋势;CO_2的吸附量变化较大,在CO_2注入比例不超过2时,吸附量先增加,在1Km左右(CO_2超临界点对应的地层深度附近)达到最大,然后开始下降,并逐渐趋于平缓,CO_2注入比例大于2时,吸附量先增加,在1Km左右达到最大,然后开始下降,之后又开始逐渐上升,并在地层5Km处时,趋于一个稳定值。随着CO_2注入比例的增加,同一地层深度处,CH_4的吸附量逐渐变小,且减小的趋势逐渐变缓;CO_2的吸附量逐渐增大,且增大的趋势逐渐变缓,而在地层5Km处时,当注入比例大于2时,CO_2的吸附量已达到饱和,不再随注入比例的增加而变化。通过对这些规律的研究和分析,并结合页岩气藏实际的开发条件,可为页岩气藏的高效开发提供一定的理论依据。
The adsorption properties of CO2/ CH4 mixture in pore structure of illite that is the clay mineral in shale reservoir are studied by the grand canonical Monte Carlo method. The simulated results show that with the increase of formation depth,in the same injection ratio of CO2,the adsorption quantity of CH4 shows a trend of ascending followed by leveling off.The adsorption quantity change of CO2 is a little large. When injection ratio is not over two,the adsorption quantity increases firstly and reaches a peak value while the formation depth is about 1 Km,which is near the corresponding depth of the supercritical point of CO2. Then it begins to decline and followed by a trend of increase again. At last,it approaches a stable value at the formation depth of 5 Km. With the increase of the injection ratio of CO2,at the same formation depth,the adsorption quantity of CH4 decreases and the trend of decline slows down gradually. Meanwhile,the adsorption quantity of CO2 increases and the trend of decline slow down gradually. When the injection ratio of CO2 is over two,the adsorption quantity of CO2 has reached the saturation and will not change with the increase of injection ratio of CO2 at the formation depth of 5km. The research and analysis of these rules combined with actual development condition of shale gas reservoir can provide certain theoretical basis for the high-efficient development of shale gas reservoir.
出处
《世界科技研究与发展》
CSCD
2016年第5期950-954,共5页
World Sci-Tech R&D
基金
国家自然科学基金面上项目(51374179)资助
关键词
页岩气
黏土矿物
巨正则蒙特卡洛
竞争吸附
shale gas
clay mineral
grand canonical Monte Carlo
competitive adsorption
