鄂尔多斯盆地本溪组碎屑障壁海岸砂体微相南北变化  

Changes from south to north in the microfacies of clasticbarrier coastal sandbodies of the Benxi Formation in the Ordos Basin

作　　者：孟祥振[1] 窦天财[2] 蒲仁海[3] 高小平[2] 刘刚[2] 宋明 樊宇洁 MENG Xiangzhen;DOU Tiancai;PU Renhai;GAO Xiaoping;LIU Gang;SONG Ming;FAN Yujie(Natural Gas Research Institute Branch,Shaanxi Yanchang PetroleumCo.,Ltd.,Xi'an 710061,China;Gas Field Company,Shaanxi Yanchang PetroleumCo.,Ltd.,Yan'an 716000,China;Department of Geology/State Key Laboratory of Continental Dynamics,Northwest University,Xi'an 710069,China)

机构地区：[1]陕西延长石油[集团]有限责任公司天然气研究院分公司,陕西西安710061 [2]陕西延长石油[集团]有限责任公司气田公司,陕西延安716000 [3]西北大学地质学系/大陆动力学国家重点实验室,陕西西安710069

出　　处：《西北大学学报（自然科学版）》2024年第3期555-568,共14页Journal of Northwest University（Natural Science Edition）

基　　金：国家自然科学重大基金项目(41390451);陕西省重点研发计划项目(2022GY-140)。

摘　　要：在延长探区近1500口钻井资料的基础上,进行大量岩心和薄片观察以及砂厚和砂地比统计,探究鄂尔多斯盆地本溪组的砂体微相类型、平面形态和分布的沿岸变化及其控制因素。结果表明,延长气田本溪组总体均为中小潮差环境下的陆源碎屑障壁海岸沉积,但南部的甘泉—富县地区波浪作用较弱,形成了典型的障壁砂坝和障壁后沉积。北部延安—靖边南地区波浪作用较强,形成了改造障壁、浅滩和下切谷充填潮道3种主要微相砂体。障壁砂体呈平行岸线的带状或串珠状排列,近源和近岸分布;浅滩砂体呈多个分散的卵圆形远源远岸分布;潮道带砂体充填则受控于古地貌凹槽。该研究结果对延长气田和类似环境的储层识别和评价具有重要的指导意义。Based on core and thin section observations,as well as statistical analyzes of sandstone thickness and percentage of sandstone content from 1446 wells,we analyzed the coastal changes and control factors of the microfacies type,planar morphology and distribution of the Benxi Fm sandbodies in the Yanchang gas field.The results indicate that the Benxi Fm of the Yanchang gas field is generally composed of terrigenous coastal clastic barrier deposits in a medium to small tidal range environment,but the wave action in the southern region is weak,forming typical barrier sandbars and backbarrier deposits.The wave actions in the north change more strongly,forming three major microfacies sandbodies:reworked barriers,shoals and incised valley filled tidal channels.The barrier sandbodies are arranged in a belt or bead-like pattern parallel to the shoreline and are distributed longshore near the provenance.The oval-shaped shoal sandbodies are dispersed further from the shoreline,and the filling of tidal channel sandbodies is controlled by ancient geomorphic grooves.This research has important guiding significance for the identification and evaluation of reservoirs in the Yanchang gas field and similar geological settings.

关 键 词：强波浪型障壁 弱波浪型障壁 浅滩 潮道 砂体规模与形态 

分 类 号：TE122[石油与天然气工程—油气勘探]