陆相页岩油不同类型储层物性差异及主控机制——以准噶尔盆地吉木萨尔凹陷芦草沟组为例  

Differences in physical properties of various types of reservoirs and main controlling mechanisms in continental shale oil reservoirs:A case study of Lucaogou Formation in Jimsar Depression,Junggar Basin

作　　者：韩登林[1,2] 陈丽丘 马斌玉 王晨晨 杜皓 闫康 王镜敏 林一鹏 HAN Denglin;CHEN Liqiu;MA Binyu;WANG Chenchen;DU Hao;YAN Kang;WANG Jingmin;LIN Yipeng(School of Geosciences,Yangtze University,Wuhan 430110,Hubei;Laboratory of Reservoir Microstructure Evolution and Digital Characterization,Sub-laboratory of Key Laboratory of Exploration Technologies for Oil and Gas Resources,Ministry of Education(Yangtze University),Wuhan 430100,Hubei)

机构地区：[1]长江大学地球科学学院,湖北武汉430110 [2]油气资源与勘探技术教育部重点实验室分室储层微观结构演化及数字表征实验室(长江大学),湖北武汉430110

出　　处：《长江大学学报(自然科学版)》2025年第1期12-20,共9页Journal of Yangtze University(Natural Science Edition)

基　　金：国家自然科学基金项目“微米-毫米级纹层尺度下的陆相页岩油差异富集机理研究——以沧东凹陷孔二段页岩为例(42302175)”。

摘　　要：准噶尔盆地吉木萨尔凹陷芦草沟组发育一套典型的混积岩,不同类型储层物性差异大。为明确“甜点”控制因素,通过镜下观察、微区扫描、氦孔隙法、背散射扫描电镜成像技术(MAPS)等实验,对储层类型进行划分,并对比不同储层物性差异及主控机制。实验结果表明,芦草沟组储层可根据沉积构造-岩石类型组合特征划分出4种类型:纹层状粉砂岩、块状粉砂岩、纹层状白云岩和块状白云岩。其中纹层状储层中溶孔更为发育,溶蚀作用更强且物性更好。分析认为,差异溶蚀是导致不同类型储层在物性和孔隙类型方面存在明显差异的主要原因,矿物成分和有机质影响了储层的溶蚀作用强度。砂屑和长石是溶蚀的物质基础,有机质生烃产生的有机酸是溶蚀流体的主要来源之一,所以砂屑、长石及有机质的含量与储层物性均呈正相关。其次,储层中的沉积构造特征对物性也有一定影响,在纹层状储层中,各种矿物成分呈条带状互层产出,有机质条带中产生的有机酸与周围粉砂质条带或砂屑条带充分接触,使得酸性流体可高效运移至储层中,从而产生大量溶孔。Lucaogou Formation in Jimsar Depression of Junggar Basin features a typical mafic rockssuccession with significantly varied physical properties among different reservoir types.To elucidate the controlling factors of“sweet spots”investigations were conducted using microscopic observations,micro X-ray fluorescence spectrometry,helium porosimetry,multiple antigen presenting system analysis,and other experiments to classify reservoir types and compare their distinct physical property and governing mechanisms.The results indicate that reservoirs in Lucaogou Formation can be categorized into four types based on sedimentary structure-lithology combinations:laminated siltstones,massive siltstones,laminated dolomite,and massive dolomite.Among these,laminated reservoirs exhibit more developed intergranular porosity,higher intensity of dissolution,and superior physical properties.Analysis suggests that differential diagenetic dissolution is the primary cause for the evident disparities in physical properties and pore types among reservoirs of different categories.Mineral composition and organic matter content influence the intensity of dissolution,with sand debris and feldspar serving as the substrates for dissolution and organic acids generated from hydrocarbon-generating as a major source of the dissolving fluids.Thus,there is a positive correlation between the content of sand debris,feldspar,organic matter with reservoir physical properties.Furthermore,sedimentary structures within the reservoirs also exert an impact on their physical properties.In laminated reservoirs,alternating bands of various mineral components facilitate intimate contact between organic acid-producing organic matter bands and surrounding siltstone or sand debris-bearing bands,promoting efficient migration of acidic fluids throughout the reservoir and leading to the formation of abundant dissolution pores.

关 键 词：溶蚀作用 纹层状储层 陆相页岩油储层 芦草沟组 吉木萨尔凹陷 

分 类 号：P618.13[天文地球—矿床学] TE122.2[天文地球—地质学]