【摘要】 为了定量评价火山岩脱CO2气量的潜力,选择松辽盆地北部火山岩进行了低温脱气实验。将火山岩加热到250℃时,脱出挥发份总量为0.0299～0.0790ml/g;其中CO2脱出量为0.0218～0.0706ml/g(0.429%～1.387%)。脱挥发份总量与其中CO2量具有良好的正线性相关;挥发份以CO2气为主,其次是N2气,还伴有H2,CO,CH4等还原性气体,以及更少量的低碳烷烃;基性火山岩比中、酸性火山岩脱出CO2数量较多。火山岩吸附大量CO2气,成为充足气源,火山岩脱出的吸附气主要是辗转而来的深源气,火山岩成为探索幔源气成藏的主要源岩,尤其是基性火山岩。估算CO2资源量,可将250℃时火山岩挥发份含量作为岩石挥发份及残余CO2量的下限值,而全岩分析的总碳含量可作为CO2脱出量的上限值。更多还原

【Abstract】 It is usually considered that the extrusive rocks are not gas source of carbon dioxide reservoirs, because most of the gas is released directly into atmosphere in the cooling process. Whereas, some researchers indicate recently that CO 2 gas of Changdedong gas reservoir is mainly adsorbed gas in volcanic rocks, and post-release of adsorbed gas is important to form the gas reservoir. In order to evaluate the potential and possibility for adsorbed CO 2 gas to form gas reservoirs quantitatively, low-temperature (250℃) degassing experiments of volcanic rocks in the northern Songliao basin were done. The amounts of released volatiles are 0.0299~0.0790ml/g, and those of CO 2 are 0.0218~0.0706 ml/g (or 0429~1387 wt%). The relationship between the amounts of volatiles and the amounts of carbon dioxide is positively linear. The major component of volatiles is carbon dioxide, and the second is N 2. There are also some associated components of deoxidized gases, such as H 2, CO, CH 4, as well as lower contents of low-carbon alkanes. Both the CO2 contents in volatiles and the degassing amounts of CO 2 have an inverse correlation with the contents of hydrocarbon. The CO 2 degassing amounts are negativly correlated with the SiO 2 contents of volcanic rocks. Volcanic rocks, particularly the basic ones, can adsorb large amounts of carbon dioxide and act as the major gas source rocks. When forecasting geological resource of carbon dioxide, the amounts of volatiles in volcanic rocks at 250℃ can be treated as the lower limit of the contents of volatiles and remnant CO 2, while the contents of total carbon as the upper limit of the amounts of degassing CO 2.更多还原