摘要
近年来鄂尔多斯盆地天环坳陷南段延长组8段(长8段)油气勘探取得重大突破,是鄂尔多斯盆地油气增储上产的新领域。作为鄂尔多斯盆地边缘的勘探新区,该区长8段油藏在油气来源、天环坳陷构造演化与油气成藏期耦合关系、油气充注过程及成藏主控因素等方面存在争议。综合烃源岩、油源追索、砂体分布、构造演化与油气充注期匹配关系,分析了研究区成藏主控因素,建立了长8段油藏动态成藏模式。研究结果表明:研究区长8段原油可划分为A、B和C 3类,其中以A类原油为主;长8段油藏存在3期油气充注,第I期为侏罗纪末期(约140~150 Ma)、第II期为早白垩世早期(约125~130 Ma)及第III期为早白垩世晚期(约100~110 Ma);研究区油气成藏及调整与构造演化关系密切,天环坳陷形成于侏罗纪末期—早白垩世,构造控制着油气充注期次,天环坳陷的形成改变了油气充注方向,烃源岩控制着油气分布规模,原地烃源岩的接续供烃弥补了油气充注不足。研究对鄂尔多斯盆地西缘下步油气勘探具有重要意义。
In recent years,major breakthroughs have been made in oil and gas exploration of the eighth member of Yanchang Formation(Chang 8 Member)in southern Tianhuan Depression,Ordos Basin,which is a new field for increasing oil and gas production in the basin.As a new exploration area on the edge of the basin,there is a lack of understanding of the source of oil and gas,the coupling relationship between the structural evolution of Tianhuan Depression and hydrocarbon accumulation period,the process of oil and gas charging and the main controlling factors of hydrocarbon accumulation.Based on the relationship between source rock,oil source correlation,sand body distribution,tectonic evolution and hydrocarbon charging period,the main controlling factors of reservoir formation are analyzed,and the dynamic accumulation model of Chang 8 reservoir is established.The results show that the Chang 8 crude oil in the study area can be divided into A,B and C,in which class A is the main crude oil.There are three stages of hydrocarbon charging in Chang 8 reservoir,the first stage is the end of Jurassic(about 140-150 Ma),the second stage is the Early Cretaceous(about 125-130 Ma)and the third stage is the late Cretaceous(about 100-110 Ma).Oil and gas accumulation and adjustment in the study ar-ea are closely related to tectonic evolution.Tianhuan Depression was formed in the Late Jurassic to Early Creta-ceous,and the structure controlled the period of oil and gas charging.The formation of Tianhuan Depression changed the direction of oil and gas charging,and source rocks controlled the scale of oil and gas distribution.This study is of great significance to next step of oil and gas exploration in the western margin of Ordos Basin.
作者
曹晶晶
刚文哲
杨尚儒
罗安湘
张晓磊
白杨
梁彦伟
CAO Jingjing;GANG Wenzhe;YANG Shangru;LUO Anxiang;ZHANG Xiaolei;BAI Yang;LIANG Yanwei(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)
出处
《天然气地球科学》
CAS
CSCD
北大核心
2023年第10期1752-1767,共16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.
关键词
油源对比
油气充注期次
成藏模式
长8段
天环坳陷
鄂尔多斯盆地
Oil-source correlation
Hydrocarbon charging period
Hydrocarbon accumulation model
the eighth member of Yanchang Formation(Chang 8 Member)
Tianhuan Depression
Ordos Basin
