准噶尔盆地东部多类型天然气的发现与勘探启示  

Discovery of multi-types of natural gases in the eastern Junggar basin and its implication for petroleum exploration

作　　者：龚德瑜 周川闽[1] 齐雪峰[1] 秦志军[2] 王瑞菊[1] 吴卫安[1] 韩琰 苗一豪 GONG Deyu;ZHOU Chuanmin;QI Xuefeng;QIN Zhijun;WANG Ruiju;WU Weian;HAN Yan;MIAO Yihao(Research Institute of Petroleum Exploration and Development(PetroChina),Beijing 100083,China;Research Institute of Petroleum Exploration and Development,Xinjiang Oil Field Company(PetroChina),Karamay,Xinjiang 834000,China;School of Geosciences and Surveying and Mapping Engineering,China University of Mining&Technology(Beijing),Beijing 100083,China;School of Energy College,China University of Geosciences(Beijing),Beijing 100083,China)

机构地区：[1]中国石油勘探开发研究院,北京100083 [2]中国石油新疆油田分公司勘探开发研究院,新疆克拉玛依834000 [3]中国矿业大学(北京),北京100083 [4]中国地质大学(北京),北京100083

出　　处：《地质学报》2024年第4期1263-1278,共16页Acta Geologica Sinica

基　　金：国家自然科学基金项目(编号41802177,42272188);中国石油前瞻性基础性技术攻关项目(编号2021DJ0206,2022DJ0507);中国石油直属院所基础科学研究和战略储备技术研究基金(编号2020D-5008-04)联合资助的成果。

摘　　要：石炭系是目前准噶尔盆地最重要也是最现实的天然气勘探目标。针对石炭系烃源岩的勘探主要围绕上石炭统巴塔玛依内山组展开,而理论上规模更大的下石炭统滴水泉组烃源岩的有效性尚无定论。同时,石炭纪火山作用频繁,盆地内部具备生成无机成因烷烃气的地质条件,但相关研究甚少。本次研究基于准噶尔盆地东部东道海子-五彩湾凹陷和白家海凸起天然气的分子组成和碳同位素特征,系统分析了天然气的成因来源和潜在的次生改造作用,共识别出4种不同类型的天然气:①来自滴水泉组的煤成气;②来自巴塔玛依内山组的煤成气;③无机成因甲烷和热成因天然气的混源气;④发生渗漏的热成因天然气。研究结果证实了准噶尔盆地东部下石炭统烃源岩的有效性,发现了无机成因烷烃气的踪迹,有望开辟盆地深层—超深层天然气勘探新领域,并提供了一个鉴别“同型不同源”天然气的典型案例。Explorations of Carboniferous petroleum system mainly focuses on the source rocks of the Upper Carboniferous Batamayineishan Formation.In contrast,the validity of the theoretically better-developed source rocks of the Lower Carboniferous Dishuiquan Formation is still inconclusive.Meanwhile,the frequent Carboniferous volcanism in the basin possesses the geological background for generating abiogenic alkane gas,but there are few related studies.Based on the molecular and stable carbon isotopic compositions of natural gas from the Dongdaohaizi-Wucaiwan sag and Baijiahai uplift in the eastern Junggar basin,this study systematically analyzed its genetic origin and potential secondary alteration and identified four different types of natural gases:①coal-derived gas from the Dishuiquan Formation;②coal-derived gas from the Batamayineishan Formation;③abiogenic methane mixed with thermogenic alkane gas;④leaked thermogenic gas.These results confirm the validity of the Lower Carboniferous source rocks in the eastern Junggar basin and also identify traces of abiogenic alkane gas,which opens up a new field of gas exploration in the deep and ultra-deep basin and also provides a typical case of identifying“homogeneous and hetero-origin”gas.

关 键 词：天然气 煤成气 无机成因气 下石炭统 准噶尔盆地 

分 类 号：P618.13[天文地球—矿床学]