致密砂岩储层孔隙结构对流体可动程度的影响及综合表征OA
Influence of pore structure of tight sandstone reservoirs on fluid mobility and comprehensive characterization
储层流体可动程度受储层物性及孔隙结构的综合影响显著,单一参数无法准确表征.为了明确孔隙结构综合表征在流体可动程度评价中的有效性,针对鄂尔多斯盆地合水地区三叠系延长组长 82 致密砂岩储层,旨在探究孔隙结构参数与流体可动程度的关系.采用核磁共振(NMR)、高压压汞(HPMI)联测的实验方法,计算有效可动流体孔隙度(φcutoff)及有效可动流体孔喉半径(rcutoff),并结合分形理论分析孔隙结构.进而使用主成分分析法(PCA)提取因子,并引入k-means聚类分析法,建立了致密砂岩流体可动程度综合评价方法.结果表明:研究区目的层孔喉类型以中小孔—中细喉为主,可动流体主要赋存在孔喉半径 0.01～1.0 μm的孔隙中;分形维数介于 2.440 0～2.741 2 之间,平均值 2.55;有效可动流体孔喉半径介于 0.016～0.095 μm之间,平均值为 0.049 μm;有效可动流体孔隙度介于 0.716%～2.980%之间,平均值为 1.598%.综合流体可动程度参数、物性参数、孔隙结构参数,提取4 个主成分,分别评估储层渗流能力与储集能力、微观非均质性、产出能力、大孔喉占比.基于前3 个主成分输出聚类结果,将实验样品划分为Ⅰ类、Ⅱ类、Ⅲ类.流体可动程度的综合评价结果可为同类型致密砂岩油藏储层评价及高效开发提供一定依据.
[Objective]Reservoir fluid mobility is significantly influenced by the combined effects of reservoir physical properties and pore structure,and cannot be accurately characterized by a single parameter.This study aims to apply a comprehensive pore structure characterization to evaluation tight sandstone reservoirs.[Methods]In this study,the effective movable fluid porosity(φcutoff)and effective movable fluid pore throat radius(rcutoff)were calculated by integrating nuclear magnetic resonance(NMR)and high-pressure mercury intrusion(HPMI)with fractal theory for the Triassic Chang 82 tight sandstone reservoir in the Heshui area of the Ordos Basin.To explore the relationship between pore structure parameters and the degree of fluid mobility in the reservoir,principal component analysis(PCA)was employed to extract factors,and k-means clustering was introduced to establish a comprehensive evaluation approach for fluid mobility of tight sandstones.[Results]The results showed that the pore throat types of the target layer in the study area were predominantly medium-small pores and medium-fine throats,and movable fluid mainly resided in pores with pore sizes of 0.01-1.0 μm.The fractal dimension ranged from 2.440 0 to 2.741 2,with an average of 2.55.The effective movable fluid pore throat radius ranged from 0.016 to 0.095 μm,with an average value of 0.049 μm.The effective movable fluid porosity ranged from 0.716%to 2.980%,with an average value of 1.598%.By integrating parameters of fluid mobility,physical properties,and pore structure,four principal components were extracted to evaluate reservoir permeability and storage capacity,microscopic heterogeneity,production capacity,and the proportion of large pore throats.Based on the clustering results from the first three principal components,the samples were classified into Class Ⅰ,Ⅱ,and Ⅲ.[Conclusion]The comprehensive evaluation results of fluid mobility can provide a basis for reservoir evaluation and efficient development of similar tight sandstone oil reservoirs.
陈琪泉;李超;成友友;谭习群;罗翔;赵子萱;闫晨辉;谭成仟
西安石油大学地球科学与工程学院,西安 710065中国石油天然气股份有限公司长庆油田分公司勘探开发研究院,西安 710018西安石油大学地球科学与工程学院,西安 710065中国石油天然气股份有限公司长庆油田分公司勘探开发研究院,西安 710018中国石油天然气股份有限公司长庆油田分公司勘探开发研究院,西安 710018西安石油大学地球科学与工程学院,西安 710065西安石油大学地球科学与工程学院,西安 710065西安石油大学地球科学与工程学院,西安 710065
天文与地球科学
联合表征孔隙结构分形维数主成分分析(PCA)k-means聚类分析流体可动程度
joint characterizationpore structurefractal dimensionprincipal component analysis(PCA)k-means clusteringfluid mobility
《地质科技通报》 2026 (2)
91-105,15
中国石油科技创新基金研究项目(2022DQ02-0202)陕西省自然科学基础研究计划项目(2024JC-YBQN-0397).
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