鄂尔多斯盆地东北部马家沟组三段古地貌、古环境及控烃作用  

Paleogeomorphology,paleoenvironment and hydrocarbon control of the third member of Majiagou Formation in Northeastern Ordos Basin

作　　者：姜海健[1,2] 李春堂[3] 倪春华[1,2] 贾会冲 王萍[1,2] 张毅[1,2] JIANG Haijian;LI Chuntang;NI Chunhua;JIA Huichong;WANG Ping;ZHANG Yi(Wuxi Research Institute of Petroleum Geology,Petroleum Exploration and Production Research Institute,SINOPEC,Wuxi,Jiangsu 214126,China;Key Laboratory of Hydrocarbon Accumulation,SINOPEC,Wuxi,Jiangsu 214126,China;Research Institute of Exploration and Development,North China Oil and Gas Branch Company,SINOPEC,Zhengzhou,Henan 450006,China)

机构地区：[1]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 [2]中国石化油气成藏重点实验室,江苏无锡214126 [3]中国石化华北油气分公司勘探开发研究院,河南郑州450006

出　　处：《东北石油大学学报》2023年第6期1-12,78,I0001,I0002,共15页Journal of Northeast Petroleum University

基　　金：中国石油化工股份有限公司科技部攻关项目(P17009-2)。

摘　　要：鄂尔多斯盆地马家沟组三段(马三段)是烃源岩发育层段。基于地震和钻井剖面资料,采用有机碳质量分数、X线衍射、镜下鉴定和主、微量元素等测试方法,研究鄂尔多斯盆地东北部马三段沉积地貌和沉积相特征,分析烃源岩品质及其与岩相和沉积相的关系,明确烃源岩发育控制因素。结果表明:鄂尔多斯盆地东北部继承性发育低隆起、台内缓坡带和凹陷,马三段发育潮坪、潟湖相碳酸盐岩与膏盐岩混积体系,沉积古坡度和古水体深度向凹陷方向逐渐变大,膏岩层厚度加大且发育频率增多;台内缓坡带膏云岩和泥云岩呈中薄层互层,Sr/Ba、V/(V+Ni)、Mg/Ca反映台内缓坡带泥云岩沉积期环境比较温暖湿润、盐度较低,是适合藻类等有机质发育的环境,在局部含藻的膏云岩层段保存大量底栖绿藻和球形蓝藻菌。热演化和酸溶有机质恢复后,马三段台内缓坡带烃源岩原始有机碳质量分数为0.81%~1.39%,为中等—好的烃源岩,泥云岩段有机质条带发育,黏土矿物质量分数较高,是最有利的烃源岩岩相类型。盆地东北部台内缓坡带是烃源岩发育的有利构造单元,泥云岩是有利的烃源岩发育岩相,研究区马家沟组盐下具有较大的勘探潜力。该结果为鄂尔多斯盆地马家沟组天然气勘探提供依据。The third member of Majiagou Formation(Ma 3rd Member)in Ordos Basin is a source rock development interval.Based on seismic and well profile data,organic carbon mass fraction,X-ray diffraction,microscopic identification,and main and trace element tests,the sedimentary landform and sedimentary facies characteristics of the third member of Majiagou Formation in the northeast of the basin are described,the quality of source rocks and their relationship with lithofacies and sedimentary facies are analyzed,and the controlling factors for the development of source rocks are identified.The results show that in the northeastern part of Ordos Basin,low uplift,gentle slope zone and depression are inherited,tidal flat and lagoon-facies carbonate and salt-rock mixed deposition systems are developed in the Ma 3rd Member.In the direction of depression,the sedimentary paleo-slope and paleo-water depth gradually increase,and the thickness and development frequency of gypsum rock strata increase.Sr/Ba,V/(V+Ni)and Mg/Ca indicate that the sedimentary environment of marcloud in the gentle slope zone is warm,moist and low in salinity,which is suitable for the development of organic matter such as algae.A large number of benthic green algae and spherical cyanobacteria are preserved in the local algae-containing pasted strata.After thermal evolution and the recovery of acid-soluble organic matter,the source rocks in the gentle slope zone of the platform of Ma 3rd Member are the most favorable source rock facies with the original organic carbon content ranging from 0.81%to 1.39%,which is a medium-good source rock.The gentle slope zone in the northeast of the basin is a favorable structural unit for the development of the source rocks,and the marcloud is a favorable lithofacies for the development of the source rocks.The subsalt exploration potential of Majiagou Formation in the study area is large.These results provide a basis for natural gas exploration in Majiagou Formation,Ordos Basin.

关 键 词：鄂尔多斯盆地 古地貌 古环境 台内缓坡带 沉积相 烃源岩 控烃作用 

分 类 号：TE121.1[石油与天然气工程—油气勘探]