玛湖凹陷致密砾岩低电阻率油层成因机理与识别方法  

Genetic Mechanism and Identification Method of Low Resistivity Tight Conglomerate Oil Layer in Mahu Depression

作　　者：曹志锋 令狐松 王先虎 王振林[2,3] 张玮 张艳丽 CAO Zhifeng;LINGHU Song;WANG Xianhu;WANG Zhenlin;ZHANG Wei;ZHANG Yanli(Xinjiang Branch,China National Logging Corporation,Karamay,Xinjiang 834000,China;Exploration and Development Research Institute of PetroChina Xinjiang Oilfield Company,Karamay,Xinjiang 834000,China;College of Petroleum Engineering,China University of Petroleum(Beijing),Beijing 102249,China)

机构地区：[1]中国石油集团测井有限公司新疆分公司,新疆克拉玛依834000 [2]中国石油新疆油田分公司勘探开发研究院,新疆克拉玛依834000 [3]中国石油大学(北京)石油工程学院,北京102249

出　　处：《测井技术》2023年第4期495-501,共7页Well Logging Technology

基　　金：中国石油天然气集团有限公司攻关性应用性科技专项“砾岩油藏规模增储上产与提高采收率关键技术研究”(2023ZZ24)。

摘　　要：为解决常规测井方法难以有效识别致密砾岩低电阻率油层的难题,利用玛湖凹陷油藏地质、岩石物理实验分析、测井、试油等资料,开展从宏观到微观的低电阻率油藏成因、主控因素及储盖融合的油层识别方法研究。研究结果表明,玛湖凹陷目的层沉积环境以扇三角洲前缘砂质碎屑流为主,储层分选差,黏土含量高,黏土类型主要为伊蒙混层,伊蒙混层具有很强的阳离子交换量。由于泥岩的欠压实性形成超压油藏,地层超压改善储层孔隙结构,发育微细裂缝,地层超压形成的微细裂缝会增强地层的导电能力。因此,黏土类型为伊蒙混层、黏土含量高、地层超压是形成研究区低电阻率油层的主要因素。基于储盖测井响应特征机理,提出储盖融合的超压物性指数、电阻率消减率识别致密砾岩低电阻率油层的新方法。研究成果为玛湖凹陷致密砾岩低电阻率油层的测井识别及勘探评价提供理论基础,该方法可应用于试油选层,助力油田高效勘探。In order to solve the problem that conventional logging methods are difficult to identify the low resistivity reservoir of tight conglomerate effectively.Based on the data of reservoir geology,petrophysical analysis,well logging and oil testing in Mahu depression,the formation,main control factors and reservoir and cap fusion identification methods of low resistivity reservoir are studied from macro to micro.The results show that the target layer of Mahu depression is dominated by sandy clastic flow in the front of fan delta.The reservoir has poor sorting and high clay content.The clay type is mainly the Yimeng mixed layer,which has strong cation exchange capacity.Due to the undercompaction of mudstone,overpressure reservoir is formed,and the formation overpressure improves the pore structure of reservoir and develops micro-cracks,which will enhance the conductivity of formation.Therefore,the type and high content of mixed layer clay and formation over pressure are the main factors for the formation of low resistivity oil layer in the study area.Based on the mechanism of reservoir-cap logging response,a new method is proposed to identify low-resistivity oil formations of tight conglomerate based on overpressure physical property index and resistivity reduction rate.The research results provide a theoretical basis for well logging identification and exploration evaluation of low resistivity tight conglomerate oil formation in Mahu sag,which can be applied to oil testing and formation selection to help efficient oil field exploration.

关 键 词：岩石物理 油层识别 致密砾岩储层 低电阻率油层 玛湖凹陷 

分 类 号：P631.84[天文地球—地质矿产勘探]