松散煤体注CO_2置驱CH_4效应实验研究
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摘要
为了研究现场试验"液态CO_2致裂煤体-置驱瓦斯"过程中相变成气态CO_2气体置换与驱替煤体CH_4主要机理及其主导作用。利用自制实验装置,进行了不同实验条件下煤体注CO_2气体置驱瓦斯模拟实验。实验结果表明:在注气初期0~50 min,2种气体组分浓度迅速上升,此过程中置换效应明显;50~300 min,气体浓度变化逐渐趋于平稳,主要依据CO_2自身特性优势,将吸附在煤体吸附域中的CH_4气体驱替出来使其沿着煤体孔裂隙渗流扩散,这一过程中驱替效应占主导作用;300 min后处于置换与驱替效应相互作用的低效置驱阶段。
To study the main mechanism and mastery reaction of CH_4 in the replacement and displacement by CO_2 in the process of "liquid CO_2 fracturing coal and gas displacement". The simulation experiment of coal seam injection with CO_2 is carried out under different experimental conditions that used experimental device by self-invented. The experimental results show that concentration of two kinds of gas increases rapidly in the 0 ~50 mins range of gas injection, the replacement effect is obvious.50~300 mins gas concentration gradually stabilized, mainly because of its own advantages by CO_2, the adsorption of CH_4 was displaced into its coal adsorption domain and spread along the seepage channel, thus the dominant effect of this process is displacement. after 300 mins replacement and displacement interacted with each other but the function is decreased in this period.
To study the main mechanism and mastery reaction of CH_4 in the replacement and displacement by CO_2 in the process of "liquid CO_2 fracturing coal and gas displacement". The simulation experiment of coal seam injection with CO_2 is carried out under different experimental conditions that used experimental device by self-invented. The experimental results show that concentration of two kinds of gas increases rapidly in the 0 ~50 mins range of gas injection, the replacement effect is obvious.50~300 mins gas concentration gradually stabilized, mainly because of its own advantages by CO_2, the adsorption of CH_4 was displaced into its coal adsorption domain and spread along the seepage channel, thus the dominant effect of this process is displacement. after 300 mins replacement and displacement interacted with each other but the function is decreased in this period.
引文
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[4]杨宏民,王兆丰,任子阳.煤中二元气体竞争吸附与置换解吸的差异性及其置换规律[J].煤炭学报,2015,40(7):1 550-1 554.
[2]GENTZIS T.Subsurface sequestration of carbon dioxide-an overview from an alberta(canada)perspective[J].International Journal of Coal Geology,2000,43(1/4):287-305.
[3]杨宏民,张铁岗,王兆丰,等.煤层注氮驱替甲烷促排瓦斯的试验研究[J].煤炭学报,2010,35(5):792-796.
[4]杨宏民,王兆丰,任子阳.煤中二元气体竞争吸附与置换解吸的差异性及其置换规律[J].煤炭学报,2015,40(7):1 550-1 554.