Stochastic Simulation And Visualization Of Permeability In The Cretaceous Aquifer Of Ordos Basin

The permeability of aquifer is studied in this thesis using stochastic equivalentcontinuum medium model. The aquifer is located in the Cretaceous Artesian Basin (CAB)of the Ordos Basin. Based on the introduction of hydrogeological conditions andlithofacies in the cretaceous, according to the methods of steady-flow, compute thepermeability with the data of pumping tests. Validate it by standard curve and beelinegraphic methods. The two values turn out to be direct correlation. Reliability ofcomputation is proved.Analyze the parameter of permeability and lithology of the borehole. The spatialdistribution is characterized by stochastic and structural features. The parameter isresearched by Geostatistics.Analyze the structural information, such as the borehole and the geological profile;build the three-dimensional geological structural model. It makes the stochastic simulationof the permeability possible.After the introduction of regionalized variable, the variograms, indicator variogramsand conditonal simulation, computer the variograms of permeability and the indicatorvariograms of lithology respectively, which are suggested to reflect the stochastic andstructural features of permeability of aquifer and lithology. According to the sequentialGaussian simulation of permeability and the sequential indicator simulation of lithology,the permeability is proved to be of heterogeneity, and lithology is of spatial variability.From the point of region, the south of the basin is less in permeability than the north, whilethe Huanhe Form is less than Luohe Form;the silt and sand stone are interbedded in thesouthern of Huanhe Form, and sand stone occurs in the most parts of the northern, withless silt.Simulate the permeability by the sequential Gaussian for 135 times, of which 120times come to steady state, indicating the model is of convergence. By the upscaling ofeach realization of conditional simulation, supply the parameter of the permeability for thenumerical simulation of water flow. Finally, the variance distribution of the water table,which is computed by each permeability realization as the parameter of aquifer, formsfoundation of availability of the numerical simulation result.