基于天文周期等时格架预测细粒沉积岩相展布——以鄂尔多斯盆地富县地区三叠系长7段为例  

Prediction of fine⁃grained sedimentary lithofacies distribution based on astronomical cycle isochronous lattice:a case study of Triassic Chang 7 member of Fuxian area,Ordos Basin

作　　者：何发岐[1] 朱建辉[2] 齐荣[1] 武英利[2] 缪九军[2] 姜龙燕[1] 王东燕[2] 陈现 HE Faqi;ZHU Jianhui;QI Rong;WU Yingli;MIAO Jiujun;JIANG Longyan;WANG Dongyan;CHEN Xian(SINOPEC North China Company,Zhengzhou,Henan 450006,China;Wuxi Research Institute of Petroleum Geology,SINOPEC,Wuxi,Jiangsu 214126,China)

机构地区：[1]中国石化华北油气分公司,郑州450006 [2]中国石化石油勘探开发研究院无锡石油地质研究所,江苏无锡214126

出　　处：《石油实验地质》2024年第5期927-940,共14页Petroleum Geology & Experiment

基　　金：中国石化科技部项目(P22179)和中国石化重大项目(P23229)联合资助。

摘　　要：预测陆相不同类型岩相厚度分布是陆相页岩油富集区带优选评价的基础工作,以此开展的不同类型岩相含油条件、储集条件以及可动条件的研究,对靶区优选和水平井段方向部署有着重要的作用。以岩心观察与测井判识为基础,开展测井资料的频谱分析,引入稳定的天文轨道时间周期,进行时空调谐,建立钻井对比的高频层序等时格架,定量计算每个层序旋回内不同类型岩相厚度的平面变化趋势,认识岩相展布规律。针对鄂尔多斯盆地南部富县地区三叠系延长组7段的研究表明,自然伽马测井曲线包括了若干组天文周期信息,其中可以识别出6个完整的稳定405 kyr长偏心率天文周期旋回,以R203井长7段全岩心段观察和测井相特征分析为基础,合理建立高频等时格架进行井间对比。结果表明,泥页岩和纹层页岩主要发育长7_(3)亚段到长7_(2)亚段的底部旋回地层,细砂岩、粉砂岩在长7_(2)亚段中上部到长7_(1)亚段底部的Ⅳ—Ⅴ旋回地层中最为发育;井间横向对比表明,早期旋回的泥页岩和纹层页岩岩相广泛分布,旋回Ⅰ时期主要分布在研究区西南部,旋回Ⅱ时期分布在西部和东—东北部,中部地区局部较厚,而Ⅳ—Ⅴ旋回地层的细砂岩厚度分布由北东—南西的沉积体系控制,平面上呈北—北东往南—南西展布,往西南延伸到ZF27—ZF32井一线,形成了长7段3种源储组合类型。其中纹层页岩与细砂岩岩相配置组合为长7_(3)亚段中上部与长7_(2)亚段中上部—长7_(1)亚段下部层系组合,平面上主要分布在富县地区的中部—北、北东部;页岩岩相厚度发育较好的为长7_(3)亚段,平面上主要分布在富县地区的北东—东部、西南部区域。Predicting the thickness distribution of different types of continental lithofacies is a fundamental task for selecting and evaluating continental shale oil⁃rich zones.Research on oil⁃bearing conditions,reservoir charac-teristics,and mobility of different types of lithofacies plays an important role in target area selection and the deployment of horizontal well sections.Based on core observation and logging identification,spectrum analysis of logging data was carried out.Stable astronomical orbital time cycles were introduced to perform spatio⁃temporal tuning.A high⁃frequency sequence isochronous lattice for drilling well comparison was established and the planar thickness variation trends of different types of lithofacies in each sequence cycle were quantitatively calculated,providing insights into lithofacies distribution patterns.Research on the 7th member(Chang 7)of Triassic Yan⁃chang Formation in the Fuxian area of the southern Ordos Basin showed that the natural gamma logging curves contained several sets of astronomical cycle information,among which 6 complete stable 405 kyr long eccentricity astronomical cycles could be identified.Based on the observation of the whole core section of Chang 7 member in well R203 and logging facies characteristics analysis,a reasonable high⁃frequency isochronous lattice was estab⁃lished for well⁃to⁃well comparison.The results showed that mud shale and laminated shale mainly developed in the bottom cyclic strata from Chang 7_(3) to Chang 7_(2) sub⁃member,and the fine⁃grained sandstone and siltstone were mostly developed in strata of cyclesⅣtoⅤfrom the middle and upper parts of Chang 7_(2) to the bottom of Chang 7_(1).Lateral comparison between wells showed that the mud shale and laminated shale lithofacies in the early cycles were widely distributed.During cycleⅠperiod,these facies were mainly distributed in the southwest of the study area,and during cycleⅡperiod,they were distributed in the west and east⁃northeast,with thicker storage in the

关 键 词：岩相 米氏旋回 长偏心率 等时格架 延长组 三叠系 富县地区 鄂尔多斯盆地 

分 类 号：TE122.2[石油与天然气工程—油气勘探]