银川平原第四系含水结构随机模拟

发布时间：2018-04-25 00:27

本文选题：银川平原 + 三维地质建模　；参考：《中国地质大学(北京)》2017年硕士论文

【摘要】：传统的含水层渗透结构模型,是在自然地质概况、水文地质概况、岩性与地质剖面等基础资料之上,对含水介质空间展布进行一个整体的概化。然而,在地质条件复杂的大型区域,含水层多以形态各异的透镜体形式分布,很难找到一个稳定而连续的含水层或者隔水层进行含水层空间结构的概化。尤其是在人类生产活动较少的地区,勘查资料与钻孔资料也相对稀少,数据通常分布不均匀且不确定性较高,钻孔之间的水文地质特征只能通过人为的推测进行描述,很难对模型中的每个单元进行准确的刻画。针对地质条件较为复杂以及地质资料不足的大型区域,若选择传统方法建立研究区含水层渗透结构,容易产生较大的人为误差,含水介质的非均质性与各向异性往往得不到准确的表达。为了进一步认识银川平原第四系含水层渗透结构特征,了解含水介质的空间分布规律以及相互关系,本文结合地质统计学理论与三维地质可视化建模的方法,实现对研究区含水层结构的随机模拟,利用数学描述的方法将高程测点、物探数据与岩性数据等离散数据,转变为连续、直观的图形与图像,从而提高含水层渗透结构建模的精度。本论文以银川平原第四系地层为研究对象,由于研究区面积较大且地质构造复杂,西部贺兰山山前倾斜平原、东部鄂尔多斯台地均缺少钻孔资料,平原区钻孔分布均匀性较差。因此,将区域地质资料、离散的钻探资料及物探数据相结合,分别建立第四系三维地质模型、导电性结构模型、岩性结构模型。进行电性与岩性结构分布的不确定性随机模型,即对视电阻率数据与岩性数据进行序贯高斯模拟,并从二维剖面的角度与已有水文地质剖面图、视电阻率剖面图、钻孔柱状图进行含水介质空间分布特征的对比验证,同时,通过对比指数模型与球状模型两种理论模型的拟合,分析其对视电阻率数据随机模拟结果的影响,最终选择连续性与成层性较好的指数模型作为第四系地层随机模拟理论模型。通过构建银川平原第四系含水层渗透结构模型,可以进一步刻画研究区第四系储层内部结构与含水介质空间分布形态,有利于地下水动力场特征深层次的研究,为促进地下水资源开发利用与保护,以及油气资源、固体矿产资源等领域的研究提供含水结构基础。
[Abstract]:The traditional aquifer permeability structure model is based on the basic data of natural geology, hydrogeology, lithology and geological profile, etc., which generalizes the spatial distribution of water-bearing media as a whole. However, in large regions with complex geological conditions, aquifers are distributed in different lens forms, so it is difficult to find a stable and continuous aquifer or aquifer to generalize the aquifer spatial structure. Especially in areas with less human production activities, the exploration data and borehole data are also relatively scarce, and the data are usually distributed unevenly and with high uncertainty. The hydrogeological characteristics between boreholes can only be described by artificial speculation. It is difficult to accurately depict each unit in the model. In view of the large area with complicated geological conditions and insufficient geological data, if the traditional method is chosen to establish the aquifer permeability structure in the study area, it is easy to produce large artificial error. The heterogeneity and anisotropy of aqueous media are often not accurately expressed. In order to further understand the percolation structure characteristics of Quaternary aquifer in Yinchuan Plain and the spatial distribution law of water-bearing medium and the relationship between them, this paper combines the theory of geostatistics with the method of 3D geological visualization modeling. The random simulation of aquifer structure in the study area is realized, and the discrete data such as elevation point, geophysical prospecting data and lithologic data are transformed into continuous and intuitionistic graphs and images by the method of mathematical description. Thus, the modeling accuracy of aquifer permeability structure is improved. In this paper, the Quaternary strata of Yinchuan Plain are taken as the research object. Because of the large area and complicated geological structure in the study area, the inclined plain in front of Helan Mountain in the west of China and the eastern Ordos platform are short of borehole data, and the distribution of boreholes in the plain is poor. Therefore, the regional geological data, discrete drilling data and geophysical data are combined to establish the Quaternary three-dimensional geological model, electrical structure model, lithologic structure model. The uncertain stochastic model of electric property and lithologic structure distribution is carried out, that is, the sequential Gao Si simulation of apparent resistivity data and lithologic data is carried out, and the existing hydrogeological profile and apparent resistivity profile are analyzed from the view of two-dimensional profile. The spatial distribution characteristics of water-bearing medium are compared and verified by the borehole histogram. At the same time, by comparing the two theoretical models of exponential model and spherical model, the influence of these two models on the random simulation results of apparent resistivity data is analyzed. Finally, the exponential model with good continuity and stratification is chosen as the theoretical model of Quaternary stratigraphic stochastic simulation. By constructing the permeability structure model of Quaternary aquifer in Yinchuan Plain, the internal structure of Quaternary reservoir and the spatial distribution of water-bearing medium in the study area can be further described, which is beneficial to the further study of the characteristics of groundwater dynamic field. In order to promote the development, utilization and protection of groundwater resources, as well as oil and gas resources, solid mineral resources and other fields to provide the basis of water-bearing structure.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P641.6;P628

【相似文献】