首页|鄂尔多斯盆地安塞地区延长组长9段原油地球化学特征与油源对比

鄂尔多斯盆地安塞地区延长组长9段原油地球化学特征与油源对比

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鄂尔多斯盆地安塞地区延长组长9段打出高产原油,勘探前景良好.本文采用有机地球化学测试分析与生物标志化合物分析方法,对安塞地区长9段原油和长7段与长9段烃源岩地球化学特征进行研究,并开展油源对比分析.结果表明:长9段原油Pr/Ph值平均为1.86,原油形成于弱还原-弱氧化环境,ααα-20R C27-C28-C29甾烷分布呈反"L"型,指示陆相高等植物为主的混合来源,C29甾烷20S/(20S+20R)为0.48~0.51,C29甾烷ββ/(αα+ββ)为0.52~0.53,表明原油均已成熟.长7段烃源岩有机质类型以Ⅱ-Ⅲ型及Ⅲ型为主,沉积于弱还原-弱氧化环境,普遍进入生油高峰期,规则甾烷相对质量分数以C29>C28>C27为主,表明与陆相高等植物输入密切相关;长9段烃源岩有机质类型主要为Ⅱ-Ⅲ型及Ⅲ型,沉积于弱还原-弱氧化环境,均进入生油高峰期,规则甾烷C29相对质量分数最高,表明与陆相高等植物成分密切相关.油源对比结果表明,安塞地区长9段原油为长7段和长9段烃源岩混合来源.
Oil Geochemical Characteristics and Oil-Source Correlation of Chang 9 Member of Yanchang Formation in Ansai Area,Ordos Basin
The Chang 9 Member of Ansai area in Ordos basin has produced high-yield crude oil,which has good exploration prospects.The geochemical characteristics of Chang 9 crude oil and Chang 7 and Chang 9 source rocks in Ansai area were studied by using organic geochemical and biomarker analysis methods,and then oil-source correlation analysis was carried out.The results show that the average Pr/Ph value of Chang 9 crude oil is 1.86,formed in a weak reduction-weak oxidation environment.The ααα-20R C27-C2s-C29 sterane configuration is inverted"L"type,indicating a mixed source dominated by terrestrial higher plants.C29 sterane 20S/(20S+20R)is 0.48-0.51 and C29 steraneββ/(αα+ββ)is 0.52-0.53,indicating that the crude oil is mature.The organic matter types of Chang 7 source rocks are mainly Ⅱ-Ⅲ and Ⅲ,deposited in a weak reduction-weak oxidation environment,and generally entered the peak oil generation period.The mass fraction of regular steranes is dominated by C29>C28>C27,indicating that they are closely related to the input of terrestrial higher plants.The organic matter types in Chang 9 are mainly Ⅱ-Ⅲ and Ⅲ,which was deposited in a weak reduction-weak oxidation environment,and has generally entered the peak oil generation period.The content of C29 in regular steranes is the highest,indicating that it is closely related to the terrestrial higher plant composition.According to the oil-source correlation,the crude oil of Chang 9 Member in Ansai area is a mixed source of Chang 7 and Chang 9 source rocks.

oil-source correlationgeochemistrybiomarkerYanchang FormationOrdos basin

惠瑞瑞、刘妍、张志升、张治东、李斌、郭爱华

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延长油田股份有限公司杏子川采油厂,陕西 延安 717400

长安大学理学院,西安 710064

油源对比 地球化学 生物标志化合物 延长组 鄂尔多斯盆地

国家自然科学基金项目陕西省自然科学基础研究计划项目

417721182023-JC-QN-0289

2024

吉林大学学报(地球科学版)
吉林大学

吉林大学学报(地球科学版)

CSTPCD北大核心
影响因子:1.062
ISSN:1671-5888
年,卷(期):2024.54(5)