沁水盆地石炭—二叠纪海陆过渡相含煤岩系页岩气地质条件及勘探潜力  

Permo-Carboniferous Marine-terrestrial Transitional Facies Coal Measures Shale Gas Geological Conditions and Exploration Potential in Qinshui Basin

作　　者：邵龙义[1] 杨致宇 房超[3] 王帅[1] 顾娇杨[3] 张文龙[3,4] 鲁静 Shao Longyi;Yang Zhiyu;Fang Chao;Wang Shuai;Gu Jiaoyang;Zhang Wenlong;Lu Jing(School of Geosciences and Surveying Engineering,CUMTB,Beijing 100083;Chongqing Institute of Geology and Mineral Resources,Chongqing 401120;China United Coalbed Methane Co.Ltd.,Beijing 100015;Qinghai Bureau of Coal Geology,Xining,Qinghai 810007)

机构地区：[1]中国矿业大学(北京)地球科学与测绘工程学院,北京100083 [2]重庆地质矿产研究院,重庆401120 [3]中联煤层气有限责任公司,北京100015 [4]青海煤炭地质局,西宁810007

出　　处：《中国煤炭地质》2021年第10期1-10,共10页Coal Geology of China

基　　金：国家自然科学基金资助项目(41572090);国家科技重大专项资助项目(2016ZX05027-001-002)。

摘　　要：为了查明沁水盆地石炭-二叠纪海陆过渡相含煤岩系页岩气的勘探潜力,对页岩层段的岩石类型、厚度展布、有机质丰度、热演化程度、有机质类型、储层特征及含气性特征等地质条件进行了研究。沁水盆地页岩可划分出4种岩石类型,即灰黑色页岩、灰色页岩、炭质页岩及灰黑色粉砂岩,主要形成于三角洲平原分流间湾、三角洲前缘、澙湖及潮坪。沁水盆地含煤岩系发育4套富有机质页岩层段,自下而上分别是太2段、太1段、山2段及山1段,虽然单层厚度较小,但累计总厚度较大,平均总厚度在4~32m;TOC含量较高,测试页岩样品整体上为有效烃源岩,含量在1.5%以上的样品约占60%;页岩镜质体反射率平均在2.0%左右,说明有机质成熟度整体处于成熟—高成熟阶段,处于较好的生气窗范围内;有机质类型整体上为III型,属于不利于生气型干酪根类型。沁水盆地页岩含气量在0.52~6.43m^(3)/t,平均为1.65m^(3)/t,已经达到工业开采的下限值。综合评价认为沁水盆地含煤岩系页岩层段具有一定的页岩气勘探潜力。To identify exploration potential of Permo-Carboniferous marine-terrestrial transitional facies coal measures shale gas in the Qinshui Basin,the paper has carried out study on geological conditions of shale segment rock type,thickness distributions,organic matter abundance,thermal evolution degree,organic matter type,reservoir features and gas-bearing property etc.The shale in Qinshui Basin can be partitioned into 4 rock types,namely black shale,grey shale,carbonaceous shale and grayish black siltstone,mainly formed in delta plain interdistributary bay,delta front,lagoon and tidal flat.Coal measures has developed 4 sets of organic matter rich shale segments,from bottom to top have Taiyuan Formation Second Member,First Member,Shanxi Formation Second Member and First Member;although single layer thickness is smaller,but cumulative total thickness larger,average total thickness 4~32m.TOC content is higher,tested shale samples are effective source rocks as a whole,samples with TOC content above 1.5% account for about 60%.Shale vitrinite reflectance averages are about 2.0%,indicated organic matter maturity as a whole in mature to highly mature stages,within better gas generation widow range.As a whole,organic matter type belongs to category Ⅲ,to the disadvantage gas generation kerogen type.Shale gas content is 0.52~6.43m^(3)/t,average 1.65m^(3)/t,has reached commercial exploitation lower limit.Integrated assessment has considered that coal measures shale segment in Qinshui Basin has certain shale gas exploration potential.

关 键 词：页岩气 海陆过渡相 含煤岩系 勘探潜力 沁水盆地 

分 类 号：P618.13[天文地球—矿床学]