松辽盆地长岭断陷沙河子组页岩孔径多重分形特征与岩相的关系  

Relationship between multifractal characteristics of pore size and lithofacies of shale of Shahezi Formation in Changling fault depression,Songliao Basin

作　　者：梁志凯 李卓[1,2] 李连霞[3] 姜振学[1,2] 刘冬冬[1,2] 高凤琳[1,2] 刘晓庆 肖磊 杨有东 LIANG Zhikai;LI Zhuo;LI Lianxia;JIANG Zhenxue;LIU Dongdong;GAO Fenglin;LIU Xiaoqing;XIAO Lei;YANG Youdong(State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(Beijing),Beijing 102249,China;Institute of Unconventional Natural Gas,China University of Petroleum(Beijing),Beijing 102249,China;Research Institute of Exploration and Development,PetroChina Changqing Oilfield Company,Xi'an 710018,China;College of Materials Science and Engineering,Chongqing University,Chongqing 400044,China)

机构地区：[1]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [2]中国石油大学(北京)非常规油气科学技术研究院,北京102249 [3]中国石油长庆油田分公司勘探开发研究院,西安710018 [4]重庆大学材料科学与工程学院,重庆400044

出　　处：《岩性油气藏》2020年第6期22-35,共14页Lithologic Reservoirs

基　　金：国家重大科技专项“中生界陆相不同盆地类型页岩气赋存方式与富集规律研究”(编号:2016ZX05034-001-005)资助。

摘　　要：为了分析不同页岩岩相孔径分布的非均质特征及其影响因素,采用CO2与N2吸附实验分别对长岭断陷沙河子组页岩的8种岩相进行了孔隙结构表征,并运用多重分形理论研究孔径分布非均质性。结果表明:对于微孔,富有机质黏土质页岩具有最大的孔体积和比表面积,富有机质混合质页岩具有最小的孔体积和比表面积;对于中—宏孔,富有机质混合质页岩具有最大的孔体积,含有机质黏土质页岩具有最小的孔体积和比表面积。随着q的增大,气体吸附曲线的广义分形维数Dq减小,多重分形奇异谱函数α-f(α)呈现连续分布,表明页岩孔径分布具有多重分形特征;在微孔中,富有机质硅质页岩孔径离散程度最弱,富有机质混合质页岩孔隙非均质性最强;在中—宏孔中,富有机质硅质页岩具有孔隙非均质性最强、孔径分布离散程度最弱的特点;微孔与中—宏孔相比,整体非均质性较低;根据偏最小二乘回归法分析结果,不同岩石组分对于岩相的影响存在显著差异,其中TOC含量是影响孔隙非均质性的主要因素。该研究成果可从多重分形理论角度揭示不同岩相的孔径分布特征差异,为松辽盆地长岭断陷沙河子组页岩储层开发提供依据。In order to analyze the heterogeneity of pore size distribution of different shale lithofacies and its influencing factors,the pore structure of eight types of shale lithofacies of Shahezi Formation in Changling fault depression was characterized by CO2 and N2 adsorption experiments,and the heterogeneity of pore size distribution was studied by multifractal theory.The results show that:for micro pores,organic-rich clay shale has the largest pore volume and specific surface area,and organic-rich mixed shale has the smallest pore volume and specific surface area;for meso-macropores,organic-rich mixed shale has the largest pore volume,and organic clay shale has the smallest pore volume and specific surface area.With the increase of q,the generalized fractal dimension Dq of gas adsorption curve decreases,the multifractal singular spectral functionα-f(α)presents a continuous distribution,indicating that the shale pore size distribution has multiple fractal features.In the micropores,the organicrich siliceous shale has the smallest dispersion of pore size distribution,however,the heterogeneity of organic-rich mixed shale is the largest.In the meso-macropores,organic-rich siliceous shale lithofacies has the strongest heterogeneity and the smallest dispersion of pore size distribution.Micropores have a lower overall heterogeneity,comparing with meso-macropores.Based on partial least squares regression analysis,there are significant differences in the influence of different rock components on lithofacies,and TOC content is the main factor affecting pore heterogeneity.Based on the multifractal theory,the research results can reveal the difference of pore size distribution characteristics from different lithofacies,and can provide guidance for shale reservoir development of Shahezi Formation in Changling fault depression,Songliao Basin.

关 键 词：多重分形维数 非均质性 陆相页岩 沙河子组 长岭断陷 松辽盆地 

分 类 号：P618.13[天文地球—矿床学]