摘要
为探究小型断陷湖盆扇三角洲的沉积形成条件、沉积特征以及纵向沉积演化规律,以二连盆地乌里雅斯太凹陷阿尔善组扇三角洲为研究对象,综合岩芯观察、岩芯分析化验、录井和测井资料,对阿尔善组扇三角洲的沉积特征及演化过程进行了详细剖析。结果表明,研究区在阿尔善沉积期构造相对简单,基底起伏不大,古气候温暖湿润,古水体较深,为形成扇三角洲沉积提供了良好的条件。阿尔善组扇三角洲砂岩颜色以灰色和浅灰色为主,水动力条件较强;砂岩成分成熟度和结构成熟度均较低,体现了近源沉积的特征;沉积砂体以水下分流河道砂和河口坝砂为主。阿尔善组自下而上分为4个砂组,其中阿Ⅳ砂组为最主要的储集层。扇三角洲的沉积演化与构造活动、湖平面变化和物源供给紧密相关,沉积演化特征明显。研究成果可对小型断陷湖盆中的扇三角洲地区后期油气资源开发和勘探提供依据。
[Objective]In the early stage of oil and gas exploration and development,scholars paid more attention to fan deltas in large and medium-sized fault basins,while systematic studies on fan deltas in small fault basins were relatively rare.In order to study the sedimentary formation conditions,sedimentary characteristics,and longitudinal sedimentary evolution laws of fan deltas in small fault basins,especially to solve the existing problems in the sedimentary evolution laws.[Methods]The sedimentary characteristics and evolution process of the fan delta of the Aershan Formation in the Wuliyasitai sag in Erlian basin were analyzed in detail by using core observation,core analysis,well logging,and other data.[Results]The study shows that during the Aershan sedimentary period,the structure of the study area was relatively simple,the base undulation was not significant,the paleoclimate was warm and humid,and the paleo-water body was relatively deep,providing favorable conditions for the formation of fan deltas.The sandstones of the Aershan Formation fan deltas are mainly gray and light gray,with strong water dynamic conditions,and the maturity of sandstone composition and structure is relatively low,showing near-source sedimentary characteristics.The main sedimentary sand bodies are submarine distributary channel sands and estuary bar sands,and the sand group A-Ⅳis the most important reservoir layer.[Conclusion]The sedimentary evolution of fan deltas is closely related to tectonic activities,lake surface changes,and source supply.Its sedimentary evolution characteristics are very obvious.This achievement helps to more accurately predict the location and distribution of favorable reservoir layers and provides an important basis for the later oil and gas resource development and exploration in the fan delta areas of small-sized faulted lake basins.[Significance]Through comprehensive analysis of multi-source data and in-depth analysis of the sedimentary characteristics and evolution process of the Aershan Formation fan deltas in the Wuliyasitai sag of the Erlian basin,the sedimentary formation conditions,sedimentary characteristics,and longitudinal sedimentary evolution laws of the fan deltas in small-sized faulted lake basins were clarified.The problems in the sedimentary evolution laws of fan deltas in small-sized faulted lake basins were solved,providing new ideas and methods for research in this field,and having important scientific significance and innovation.
作者
任江丽
李君
张云德
王婷娟
杨宁波
徐紫烨
王乾
王玥
REN Jiangli;LI Jun;ZHANG Yunde;WANG Tingjuan;YANG Ningbo;XU Ziye;WANG Qian;WANG Yue(State Key Laboratory of Nuclear Resources and Environment,East China University of Technology,Nanchang 330013,China;School of Earth Sciences,East China University of Technology,Nanchang 330013,China;Key Laboratory for Digital Land and Resources of Jiangxi Province,East China University of Technology,Nanchang 330013,China;Second Gas Production Plant,Changqing Oilfield Company,PetroChina,Xi’an 710200,China)
出处
《东华理工大学学报(自然科学版)》
北大核心
2025年第3期238-250,共13页
Journal of East China University of Technology(Natural Science)
基金
国家重大专项子课题项目(2017ZX05008-004-004-001)
东华理工大学博士科研启动基金项目(DHBK2019041)。
关键词
演化规律
沉积特征
扇三角洲
阿尔善组
乌里雅斯太凹陷
evolvement law
sedimentary characteristic
fan delta
Aershan Formation
Wuliyasitai sag
