采用多点地质统计法重构页岩的数字岩心

发布时间：2018-04-30 04:20

本文选题：重构 + 页岩　；参考：《天然气工业》2017年09期

【摘要】：由于实验设备获得的页岩岩样大多是微米或毫米尺度,如果要获得更大尺度和范围内的孔隙结构,必须通过对其特征的三维重构才能实现。为此,提出了基于纳米精度的体数据与多点地质统计方法的页岩三维数字岩心重构方法。以页岩纳米CT数据为训练图像,使用数据模板提取其中的结构特征,通过多点地质统计方法将结构特征重构到数字岩心中;形成了以变差函数曲线、孔隙直径分布和孔隙连通性来判别重构岩心与真实页岩结构相似度的判别方法 ;基于格子玻尔兹曼方法验证了相似度评价方法。结果表明:(1)变差函数可以检验重构岩心与真实岩心的空间相似性,孔隙直径分布和孔隙连通性可以检验流动特征的相似性;(2)当变差函数曲线、孔隙直径分布和孔隙连通性相似时,重构岩心与真实岩心的渗透率相近,表明所提出的重构方法与结构相似度评价方法是有效的;(3)由于强非均质性,不同位置的重构页岩岩心渗透率差异可超过100倍。该研究成果对构建三维大尺寸强非均质性页岩数字岩心、认识页岩孔隙结构、分析流动规律具有指导作用。
[Abstract]:Because the shale samples obtained by the experimental equipment are mostly in the micrometer or millimeter scale, if the pore structure is to be obtained on a larger scale and in a wider range, it must be realized through the three-dimensional reconstruction of its characteristics. Therefore, a 3D digital core reconstruction method based on volume data and multi-point geostatistics is proposed. Using shale nano-CT data as training image and using data template to extract the structural features, the structural features are reconstructed into digital core by multi-point geostatistical method, and the variation function curve is formed. The similarity between reconstructed core and real shale structure is judged by pore diameter distribution and pore connectivity, and the similarity evaluation method is verified based on lattice Boltzmann method. The results show that the variation function can test the spatial similarity between reconstructed core and real core, and pore diameter distribution and pore connectivity can test the similarity of flow characteristics. When the pore diameter distribution and pore connectivity are similar, the permeability of reconstructed core is similar to that of real core, which indicates that the proposed reconstruction method and structural similarity evaluation method are effective due to strong heterogeneity. The permeability differences of reconstructed shale cores at different locations can exceed 100 times. The research results can be used to construct 3D large size and strong heterogeneity shale digital core, to understand shale pore structure and to analyze the flow law.
【作者单位】：页岩油气富集机理与有效开发国家重点实验室;中国石化石油工程技术研究院;
【基金】：国家科技重大专项“高压低渗油气藏固井完井技术”(编号:2016ZX05021-005) 中国石化科技攻关项目“页岩气井试井分析及产能评价技术研究”(编号:P15018) 北京市科技成果转化项目:“页岩气数字岩心建模及微纳米激光3D打印技术研究”(编号:Z171100002317016)
【分类号】：P618.13;P628.2

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