塔河地区奥陶系碳酸盐岩储层深部热液特征分析  

Analysis of characteristics of deep hydrothermal fluids in Ordovician carbonate reservoir in Tahe area

作　　者：李辉[1] 李国蓉[1] 罗韵[1] 符浩[1] 高鱼伟 朱永源[2] 张文 

机构地区：[1]成都理工大学油气藏地质及开发工程国家重点实验室,四川成都610059 [2]四川省核工业地质局二八二大队,四川德阳618000 [3]中国石油华北油田公司第二采油厂,河北霸州065700

出　　处：《东北石油大学学报》2014年第6期12-21,5-6,共10页Journal of Northeast Petroleum University

基　　金：国家自然科学基金项目(41272150)

摘　　要：塔里木盆地在海西晚期（二叠纪）发生过一次强烈的岩浆—火山活动,钻井揭示塔河地区奥陶系受到深部热液流体改造作用.为了确认深部热液流体活动,采用岩心观察、薄片鉴定、热液成因缝洞方解石地球化学分析及流体包裹体分析等方法,分析热液流体的性质及热液溶蚀作用对碳酸盐岩储层的影响.结果表明：塔河地区热液现象、热液矿物及热液矿物组合典型;δ18 O值较低,富含Ba、Mn微量元素,稀土元素显示明显的正Eu异常,87Sr/86Sr值多高于碳酸盐岩围岩;流体包裹体均一温度主要集中于130~190℃,出现3个主峰值,分别为140、160、180℃.塔河地区热液活动异常明显,来源于地壳中深部热液流体具有高温、高盐度、酸性,富含87Sr、Ba、Mn等元素,多期次性的特点,伴随热液活动所形成的溶蚀孔洞对奥陶系储层的形成有重要贡献.During the late Hercynian(Permian),there had been an intense magma-volcanic activity in Tarim basin.The well drilling revealed that the Ordovician had been modified by deep hydrothermal fluid in Tahe area.The identification of cores and thin sections,the method of geochemical analysis and mineral fluid inclusion were used on hydrothermal calcite by the study to further confirm the deep hydrothermal fluid activity.The results show:(1)The typification of hydrothermal phenomenon,hydrother-mal mineral and hydrothermal mineral assemblage,(2)low18 O value,the trace elements are rich in Ba and Mn elements,REE show obvious positive Eu anomaly,and the 87Sr/86 Sr value is much higher than surrounding carbonate rock,(3)The fluid inclusion homogenization temperatures of hydrothermal calcite mainly converge between 130~190 ℃,and three main different peaks,140 ℃,160 ℃ and 160 ℃.Hydrothermal activity is especially obvious in Tahe area,The deep hydrothermal fluids derived from the crust,with high temperature and high salinity,with the characteristics of multi-stages,rich acid materials and 87 Sr,Ba,Mn.The dissolved pores formed by hydrothermal activity played an important role in Ordovician carbonate reservoir.

关 键 词：塔河地区 奥陶系 深部热液流体 热液矿物 地球化学特征 流体包裹体 碳酸盐岩储层 

分 类 号：P736[天文地球—海洋地质] TE122.1[天文地球—海洋科学]