辽河坳陷东部凹陷煤系成因生物气特征及勘探突破  

Characteristics and exploration breakthrough of coal measure genetic biogas in Eastern Sag of Liaohe Depression

作　　者：陈星州 郭强[1] 张斌[1] 韩宏伟[1] 孙新宇 刘岩[1] 杜新军[1] Chen Xingzhou;Guo Qiang;Zhang Bin;Han Hongwei;Sun Xinyu;Liu Yan;Du Xinjun(PetroChina Liaohe Oilfield Company;College of Geoscience,China University of Petroleum(Beijing))

机构地区：[1]中国石油辽河油田公司 [2]中国石油大学(北京)地球科学学院

出　　处：《中国石油勘探》2024年第1期76-91,共16页China Petroleum Exploration

基　　金：国家科技重大专项“大型油气田及煤层气开发”课题“渤海湾盆地北部油气富集规律与油气增储领域研究”(2016ZX05006-005);辽宁省“兴辽英才计划”(XLYC2007116)。

摘　　要：辽河坳陷东部凹陷是我国最早发现生物气的地区之一,勘探早期由于中深层勘探效果较好,对浅层生物气一直未重视,缺乏对浅层生物气源岩和分布规律的正确认识。在对已钻井发现浅层气(藏)地球化学特征开展系统分析基础上,以碳同位素值等为重要指标,将东部凹陷浅层气划分为原生生物气、生物—过渡带气、改造型生物气和混合气4种类型;进一步探讨了浅层气成因,认为研究区内浅层生物气主要为煤系地层成因;深化研究形成了浅层生物气分布明显受煤系地层、碎屑岩优质储层、沙河街组沙三上亚段和沙一段两套区域性封盖层等因素控制,构造晚定型、油气晚期充注成藏有利于形成浅层气的规模富集等地质认识。以此为指导,发现了高产工业气流井与规模储量,开辟了辽河坳陷煤系成因生物气勘探新局面。The Eastern Sag of Liaohe Depression is one of the areas with the earliest biogas discoveries in China.The shallow biogas has not attracted much attention in the early exploration stage due to the good exploration results in the middle and deep formations,and there is a lack of understanding of source rocks and distribution law of shallow biogas.The geochemical characteristics of shallow gas(reservoir)in drilled wells are systematically analyzed,and a key index of carbon isotope is used to classify shallow gas(reservoir)in Eastern Sag into four types,including primary biogas,bio-transitional zone gas,transformed biogas and mixed type gas.Furthermore,the genesis of shallow gas is discussed,and it is indicated that the shallow biogas is dominated by coal measure genesis.The in-depth study supports to obtain geological understanding that the distribution of shallow biogas was distinctly controlled by coal measure strata,high-quality clastic rock reservoirs,two sets of regional cap rocks in the upper sub-member of the third member of Shahejie Formation(Es31)and the first member of Shahejie Formation(Es1),and the late formation of structures and late gas charging were conducive to the large-scale gas enrichment in shallow formations.Guided by the above understanding,high-yield gas wells and large-scale reserves have been discovered,opening up a new exploration field of coal measure genetic biogas in Liaohe Depression.

关 键 词：东部凹陷 浅层气 煤系成因生物气 煤系地层 晚期成藏 

分 类 号：TE122.1[石油与天然气工程—油气勘探]