羌塘盆地托纳木地区上侏罗统索瓦组油气充注期次及成藏过程  

Charging Period and Accumulation Process of Upper Jurassic Sowa Formation in Tonamu Area,Qiangtang Basin

作　　者：洪馗斌 谢渊[3] 宋春彦[2,4] 彭清华 HONG Kuibin;XIE Yuan;SONG Chunyan;PENG Qinghua(Chengdu University of Technology,Chengdu 610059;Chengdu Geological Survey Center,China Geological Survey,Chengdu 610082;China Geologial Survey military-civilian integration geological Survey Center,Chengdu 610082;Key Laboratory of Sedimentary Basins and Petroleum Resources,Ministry of Natural Resources,Chengdu 610082)

机构地区：[1]成都理工大学,成都610059 [2]中国地质调查局成都地质调查中心,成都610082 [3]中国地质调查局军民融合地质调查中心,成都610082 [4]自然资源部沉积盆地与油气资源重点实验室,成都610082

出　　处：《四川地质学报》2024年第2期233-240,共8页Acta Geologica Sichuan

基　　金：国家自然科学基金项目(41502112);西藏科技厅重点研发计划(XZ202101ZY0014G);西藏自治区科技重大专项(XZ202201ZD0004G05)。

摘　　要：上侏罗统是羌塘盆地最为重要的油气勘探目的层之一,油气成藏期次研究有助于判断油气成藏过程及油气藏的分布规律。本文以区内油气显示良好的羌资3井上侏罗统索瓦组为研究对象,开展了流体包裹体岩相学、测温和拉曼成分研究等。结果表明,索瓦组发育大量气相、液相、气液两相流体包裹体,宿主矿物包含石英和方解石两类,包裹体产出形态多样,可细分出5小类;均一温度介于69.4~262.3℃,以90~100℃的包裹体为主,共划分出80~100℃、130~150℃、160~190℃三期油气充注流体和一期>200℃的热液流体活动。激光拉曼测试表明羌资3井包裹体主要为气相CH_(4)、液相CH_(4)和液相H_(2)O三类。结合埋藏史,推断该区经历了晚侏罗世牛津期(约160Ma)、白垩纪阿尔比期(约112Ma)以及新近纪塞拉瓦勒期(约13Ma)三期油气充注,羌资3井多阶段的油气充注和成藏进一步表明羌塘盆地上侏罗统油气目的层具有非常广阔的油气勘探前景。The Upper Jurassic is one of the most important target layers for oil and gas exploration in Qiangtang Basin.The study of hydrocarbon accumulation stages is helpful to judge the hydrocarbon accumulation process and the distribution law of oil and gas reservoirs.The upper Jurassic Sowa formation of Qiangzi 3 well shows good indication of oil and gas in the area.Taking the upper Jurassic Sowa formation of Qiangzi 3 well as the research object,the fluid inclusion petrography,temperature measurement and Raman composition research have been carried out.The results show that a large number of gaseous,liquid and gas-liquid two-phase fluid inclusions are developed in quartz and calcite from the Sowa Formation.The inclusions are in various forms and can be subdivided into 5 subclasses.The homogenization temperature ranges from 69.4℃to 262.3℃,and the inclusions are mainly 90℃to 100℃.The three phases of oil-gas charging fluid are 80℃to 100℃,130℃to 150℃,160℃to 190℃,respectively,and the first phase of hydrothermal fluid activity is>200℃.Laser Raman analysis shows that the inclusions of Qiangzi 3 well are mainly gas phase CH_(4),liquid phase CH_(4) and liquid phase H_(2)O.Combined with the burial history,it is inferred that this area experienced three stages of hydrocarbon charging:Late Jurassic Oxford(about 160Ma),Cretaceous Albian(about 112Ma)and Neogene Serravalian(about 13Ma).The multi-stage oil and gas charging and accumulation of Qiangzi 3 well further indicate that the Upper Jurassic oil and gas target layer in Qiangtang Basin has a very broad oil and gas exploration prospect.

关 键 词：羌塘盆地 流体包裹体 索瓦组 油气成藏 

分 类 号：P536[天文地球—古生物学与地层学]