塔里木盆地塔河油田中下奥陶统鹰山组内幕储层成因机理  

Genetic mechanism of inner reservoirs of Yingshan Formation of Middle-Lower Ordovician in Tahe Oil Field,Tarim Basin

作　　者：吕艳萍[1] 吕晶[1] 徐想东 邓光校[1] 刘永立[1,3] 刘存革[4] 张振哲 韩拥强[5] LU Yanping;LV Jing;XU Xiangdong;DENG Guangxiao;LIU Yongli;LIU Cunge;ZHANG Zhenzhe;HAN Yongqiang(Research Institute of Petroleum Exploration and Production,Northwest Oilfield Branch Company,SINOPEC,Urumqi,Xinjiang 830011,China;CNOOC International Ltd.,Beijing 100028,China;Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education,China University of Geosciences(Wuhan),Wuhan,Hubei 430074,China;College of Petroleum Engineering,Guangdong University of Petrochemical Technology,Maoming,Guangdong 525000,China;Xinjiang Bota Oilfield Technical Service Co.,Ltd.,Korla,Xinjiang 841000,China)

机构地区：[1]中国石化西北油田分公司勘探开发研究院,乌鲁木齐830011 [2]中国海洋石油国际有限公司,北京100028 [3]中国地质大学(武汉)构造与油气资源教育部重点实验室,武汉430074 [4]广东石油化工学院石油工程学院,广东茂名525000 [5]新疆博塔油田技术服务有限公司,新疆库尔勒841000

出　　处：《石油实验地质》2021年第6期1031-1037,共7页Petroleum Geology & Experiment

基　　金：中国石化科技部项目“岩溶系统描述及空间结构井网构建研究”(P20042)资助。

摘　　要：塔里木盆地塔河油田中下奥陶统顶部风化壳缝洞型储集体是主力产层,在其下部依然发育规模性储集体,为探讨这套储集体的成因机理,在A井区开展了碳氧同位素、锶同位素、稀土元素和阴极发光等分析测试工作。洞穴和构造裂缝方解石的δ^(18)O和δ^(13)C值明显比灰岩背景值偏负,具有δ^(18)O不变而δ^(13)C可变的趋势,δ^(18)O_(PDB)均值为-14.74‰,为脱气作用形成的大气水方解石线。洞穴和构造裂缝方解石的^(87)Sr/^(86)Sr比值介于0.709622~0.709968之间,明显高于背景值,主要受壳源锶的影响;稀土元素中Ce和Eu元素无正异常,表明缺乏热液流体的参与。洞穴和构造裂缝方解石胶结物主要发橘黄色和暗棕色光,代表的是弱氧化—弱还原环境。研究认为,A井区中下奥陶统鹰山组缝洞储集体形成于海西早期大气淡水深部缓流带环境,该岩溶环境具有承压、水流缓慢、不受排水基准面控制的特点。The fracture-cave reservoirs of weathering crust on the top of Middle-Lower Ordovician in the Tahe Oil Field of Tarim Basin are the major production layer,and large scale reservoirs are also developed underneath the reservoirs.In order to discuss the genetic mechanism of formation of these reservoirs,carbon and oxygen isotope,strontium isotope,rare earth elements and cathodoluminescence were tested in the well A area.The δ^(18)O and δ^(13)C values of calcite in caves and structural fractures are obviously negative than those in limestone background.The mean value of δ^(18)O_(PDB) is -14.74‰,showing a trend of constant δ^(18)O and variable δ^(13)C,which are the calcite lines of atmospheric water formed by degassing.The ^(87)Sr/^(86)Sr ratios of calcites from caves and structures range from 0.709622 to 0.709968,which are obviously higher than the background values,and are mainly affected by crustal strontium.There are no positive anomalies in Ce and Eu elements,indicating that there is no hydrothermal fluid involved.The cathodoluminescence of calcites are mainly orange and dark brown,which represents weak oxidation-reduction environment.The results showed that the fracture-cave reservoirs of the Midde-Lower Ordovician Yingshan Formation in the well A area were formed in the deep slow flow zone of atmospheric water during the Early Hercynian,showing the characteristics of pressure bearing,slow flow and not controlled by the karst drainage base level.

关 键 词：大气水方解石线 深缓流带 储层成因 鹰山组 中下奥陶统 塔河油田 塔里木盆地 

分 类 号：TE122.21[石油与天然气工程—油气勘探]