鄂尔多斯盆地西南缘平凉地区长8油藏油源对比及油气充注特征  

Oil-source correlation and hydrocarbon charging characteristics of Chang 8 reservoir in the Pingliang area, southwestern Ordos Basin

作　　者：曹晶晶 刚文哲[1,2] 杨尚儒 罗安湘[4] 张晓磊[4] 白杨 梁彦伟 Jingjing CAO;Wenzhe GANG;Shangru YANG;Anxiang LUO;Xiaolei ZHANG;Yang BAI;Yanwei LIANG(State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum,Beijing 102249,China;College of Geosciences,China University of Petroleum,Beijing 102249,China;Oil and Gas Technology Research Institute,PetroChina Changqing Oilfield Company,Xi’an 710018,China;Research Institute of Exploration and Development,PetroChina Changqing Oilfield Company,Xi’an 710018,China)

机构地区：[1]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [2]中国石油大学(北京)地球科学学院,北京102249 [3]中国石油长庆油田分公司油气工艺研究院,陕西西安710018 [4]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：《天然气地球科学》2024年第1期149-163,共15页Natural Gas Geoscience

基　　金：中国石油长庆油田分公司勘探开发研究院项目“平凉北地区长8原油特征分析及其成藏主控因素”(编号:技2021-38)资助~~。

摘　　要：鄂尔多斯盆地西南缘平凉地区是近年来盆地边缘增储上产的重要勘探新区,受多期构造运动影响,该区油气勘探程度低,长8段油藏油气来源及成藏规律存在争议。通过烃源岩有机地球化学特征、油源对比、烃源岩生烃期与成藏期匹配关系、储层特征及构造演化对油气充注过程的影响等方面的研究,明确了研究区长8段油气来源及运聚规律,建立了油气成藏模式。结果表明:研究区长73亚段黑色页岩有机质丰度高,干酪根类型主要为Ⅰ型,处于成熟阶段,以生油为主,长8段原油来源于长73亚段黑色页岩。长73亚段和长8段暗色泥岩有机质丰度低,干酪根类型为Ⅱ—Ⅲ型,不具有生烃贡献。研究区长8段油藏流体包裹体呈蓝色荧光,均一温度介于115~130℃之间,存在Ⅰ期油气充注。研究区长73亚段黑色页岩主生烃期与长8段油藏油气充注期相匹配,生烃高峰期和成藏期均为早白垩世末期(约100 Ma)。研究区构造呈现“西高东低”特征,发育高角度断裂,长8段储层物性较好、微裂缝发育,长73亚段黑色页岩生成的油气沿断裂向长8段储层中运移,构造高部位控制着长8段油气分布。研究对盆地边缘新区的下一步勘探部署具有重要意义。In recent years,Pingliang area is an important exploration area for increasing production on the edge of the Ordos Basin.Due to the influence of multi-stage tectonic movements,the degree of hydrocarbon exploration in this area is low,and the accumulation mechanism of Chang 8 reservoir is controversial.In this paper,by studying the organic geochemical characteristics of source rocks,oil-source correlation,the relationship between hydrocarbon generation period and charging period of source rocks,reservoir characteristics and the influence of tectonic evolution on hydrocarbon charging process are studied to clarify the oil and gas source,the migration and accumulation mechanism of Chang 8 Member in the study area,and the accumulation model is established.The results show that the black shale of Chang 73 sub-member in the study area has high organic matter abundance,and kerogen type is mainly type I,which is in mature stage and mainly generates oil.The crude oil of Chang 8 Member is generated from the black shale of Chang 73 sub-member.The dark mudstones of Chang 73 sub-member and Chang 8 Member have low organic matter abundance,and kerogen types are II-III,which does not contribute to hydrocarbon generation.The fluid inclusions of Chang 8 reservoir in the study area show blue fluorescence,with homogeneous temperatures ranging from 115℃to 130℃,and there is phase I hydrocarbon charging.The main hydrocarbon generation period of the Chang 73 sub-member black shale in the study area matches the hydrocarbon charging period of the Chang 8 reservoir,and the hydrocarbon generation peak and charging period are both late Early Cretaceous(about 100 Ma).The study area is characterized by“high in the west and low in the east”,with high-angle fractures,good physical properties and microfractures in Chang 8 reservoir.The hydrocarbon generated by the black shale of Chang 73 sub-member migrated along the fractures to the Chang 8 reservoir,and the high part of the structure controls the hydrocarbon distribution in Chang 8 rese

关 键 词：黑色页岩 流体包裹体 油源对比 油气充注 平凉地区 鄂尔多斯盆地 

分 类 号：TE121.1[石油与天然气工程—油气勘探]