松辽盆地北部火山岩CO_2脱气参数及其对CO_2资源量估算的意义  

Degassing Parameter of Carbon Dioxide in Volcanic Rocks in the Northern Songliao Basin and Its Significance in Forecasting Geological Resource of Carbon Dioxide

作　　者：刘德良[1] 李振生[1] 孙岩[2] 谈迎[1] 刘波[1] 吴小奇[1] 杨晓勇[1] 

机构地区：[1]中国科学技术大学地球与空间科学学院,合肥230026 [2]南京大学地球科学系,南京210093

出　　处：《高校地质学报》2006年第2期223-227,共5页Geological Journal of China Universities

基　　金：国家自然科学基金项目(40472074;40172072);国家重点基础研究规划专题(2001CB209133)

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。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 CO2 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 CO2 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 CO2 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 N2. There are also some associated components of deoxidized gases, such as H2, CO, CH4, as well as lower contents of low-carbon alkanes. Both the CO2 contents in volatiles and the degassing amounts of CO2 have an inverse correlation with the contents of hydrocarbon. The CO2 degassing amounts are negativly correlated with the SiO2 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 CO2, while the contents of total carbon as the upper limit of the amounts of degassing CO2.

关 键 词：火山岩 脱气参数 CO2气 松辽盆地北部 

分 类 号：P588.14[天文地球—岩石学]