Based On Multi-point Geostatistics Fracture System Modeling And Its Application Research

Accurate description of fractured media is the prerequisite for the connectivity and permeability evaluation of the rock mass structure of the geological repository for high-level radioactive waste.Multi-point geostatistics can describe the spatial heterogeneity of complex geological bodies and reproduce the geometry of some geological bodies.form.Based on multipoint geostatistics and fracture characteristic statistical data,homogeneous areas are divided,and a two-dimensional and three-dimensional network model of the fracture system is established.Against this background,the main work and research conclusions of this article are as follows:(1)Self-compiled program to divide the dominant group,and combine the multi-point geostatistics to divide the homogeneous area.Compress the three-dimensional fissures to the two-dimensional outcrop surface,realize the dimensionality reduction of the spatial fissures,and divide the dominant group according to the geometric characteristics of the fissures,and combine the multi-point geostatistics to divide the homogeneous area of the fissures in two ways,and divide it The method is evaluated to verify its reliability.(2)Monte Carlo and multi-point geostatistics were used to construct the two-dimensional model of the fracture system.Determine the fracture trace length and occurrence distribution form,focus on the improvement of multi-point geostatistics algorithm,discuss the influence of different parameter settings;use morphology to repair and reproduce the fractures,effectively reduce the formation of "fractures";by comparing the two The simulation results obtained by these modeling methods can reflect the statistical characteristics of the fracture system to a certain extent,but with multi-point geostatistics modeling,the model can better reflect the spatial correlation of the fractures.(3)Propose an improved method for the establishment of a three-dimensional network model of structural planes and conduct effective evaluation.Explains the steps of the improvement method in detail,as well as the method of obtaining the size,occurrence,and center position of the structural plane;the structural plane is regarded as a disc,and the multipoint geostatistics and the Monte Carlo method are combined by one The deterministic outcrop surface is translated to obtain a three-dimensional fracture network model.The evaluation of the model proves that the modeling method is basically feasible.(4)The modeling method is applied to the example,and the Beishan outcrop is selected for example analysis,and the construction of two-dimensional fracture network model,morphological repair,and three-dimensional fracture network model construction are carried out.The geometric feature statistics and trace length of rock mass structural planes are also involved.And the establishment of probability distribution model of occurrence,the design of structural area density statistics and other program design,and the reliability of the obtained model is analyzed at the same time,so that the method can be used in actual engineering.