鄂尔多斯东南部上古生界混积层沉积特征  

Sedimentary Characteristics of Upper Paleozoic Mixed Deposits in Southeastern Ordos

作　　者：刘桂珍 张丹丹[2] 李盼 LIU Guizhen;ZHANG Dandan;LI Pan(School of earth sciences and engineering,Xi′an Shiyou University,Xi′an,Shaanxi 710065,China;Research Institute of Petroleum Exploration and Development,Changqing Oilfield Company,PetroChina,Xi′an,Shaanxi 710018,China)

机构地区：[1]西安石油大学地球科学与工程学院,陕西西安710065 [2]中国石油长庆油田分公司勘探开发研究院,陕西西安710018

出　　处：《西南石油大学学报（自然科学版）》2018年第2期25-34,共10页Journal of Southwest Petroleum University(Science & Technology Edition)

基　　金：国家自然科学基金(41602156;41372148)

摘　　要：为了认识鄂尔多斯盆地东南部本溪组、太原组混合沉积特征,利用区域地质、钻/测井和岩芯资料,对碳酸盐-碎屑岩混合沉积层进行了研究。结果表明,本溪组—太原组既是带障壁海岸的海陆过渡相沉积,又是混合沉积;本溪组混积层岩性组合主要为碎屑岩、煤层夹灰岩,而太原组为灰岩夹泥岩及煤层组成;本溪组发育混积相类型为混积潮坪、混积瀉湖、混积障壁砂坝,太原组发育混积台地;结合区域沉积资料总结出了两种沉积相组合模式——本溪组发育混积障壁海岸相、太原组发育混积陆棚相;构造、海平面变化和气候是影响混积发育和组合模式的主要因素,其中,陆表海多期次海侵是混积主要原因。混合沉积决定了本溪组具有丰富的烃源岩、优质储集体和多套生储盖组合,是油气富集的有利层位。To identify the mixed sedimentary characteristics of the Benxi and Taiyuan formations in the southeastern part of the Ordos Basin,research was performed on mixed carbonate-clastic sedimentary layers using information derived from the region′s geology,and data obtained from well logging/drilling and rock cores.Results indicate that the Benxi-Taiyuan formations are land and sea transitional facies deposits with barrier coasts,as well as mixed sediments.Lithologically,the mixed sediments in the Benxi Formation are mainly comprised of clastic rocks and limestone sandwiched between coal seams,while the Taiyuan Formation is mainly composed of argillaceous limestone and coal seams.The mixed sediment facies developed in the Benxi Formation include mixed tidal flat sediments,mixed lagoon sediments,and mixed barrier bar sediments,whereas mixed platform sediments were developed in the Taiyuan Formation.It was concluded on the basis of the region′s sedimentation data that there were two modes of assemblage for the sedimentary facies:mixed barrier coast facies(developed in the Benxi Formation)and mixed continental shelf sedimentary facies(developed in the Taiyuan Formation).The main factors affecting the development of mixed sediments and their mode of assemblage were found to be tectonics,changes in sea level,and climate;in particular,mixed sedimentation was mainly caused by Multi level marine transgressions.Rich-source rocks,high-quality reservoirs,and multiple reservoir-caprock assemblages within the Benxi Formation were developed from these mixed sedimentary layers,and are highly favorable strata containing rich reserves of oil and gas.

关 键 词：鄂尔多斯盆地 上古生界 混积层 沉积模式 

分 类 号：TE122[石油与天然气工程—油气勘探]