Three-dimensional Geological Modeling Of The Upper Section Of Bayingobi Formation In The Preselected Section Of Tamusin In Inner Mongolia And Its Geological Significance

Deep geological disposal isa relatively common and reasonable strategy of high-level radioactive waste disposal for long-term storage of radioactive materials.In the early stage of the development of high-level radioactive waste disposal,China gave priority to granite as the disposal surrounding rock for research,and now it has entered the stage of underground laboratory construction.Subsequently,in the 21 st century,China’s attention to clay rock is also gradually increasing,and a series of research on clay rock sites have been carried out successively.The Beijing Institute of Geology of the Nuclear Industry and East China University of Technology have proposed key pre-selection areas,and the Tamusu area of Inner Mongolia is one of the pre-selection areas for clay rock repositories,and the research area is also within the uranium exploration area.The spreading and non-homogeneous characteristics of its cryptic three-dimensional space are not yet clear.A large amount of geological modeling work has not been carried out for the subsequent sedimentary phase(petrographic and diagenetic)models,adaptive property models,spatial inscription of target bodies,etc.At present,the underground spatial distribution range and thickness of clay rock,and the relationship between it and uranium ore bodies are unclear.Basin in Inner Mongolia is selected as the research object.In this paper,The upper member of Bayingebi Formation located in the Yingejing depression of Bayinggebi.Its structural model,lithofacies model and attribute model are constructed by use of 3D geological modeling technologies based on geological statistical analysis of main seismic,well data and analysis test data.Firstly,using the single well data and seismic data as well as fault data,after analyzing and comparing the fault model and the level model respectively,a quadrilateral grid,i.e.,a brick grid,was used to construct a tectonic model,a sequential indication simulation method was selected to establish a petrographic model,and a stochastic Gaussian function simulation was used to establish a property model to reveal the spatial spreading characteristics and distribution law of the subsurface of favorable claystone(mudstone)and potential uranium exploration targets.The geological significance is discussed and it is concluded that the pre-selected area of Tamusu meets the basic guidelines of claystone site screening in terms of mudstone thickness,spreading range and spatial allocation of mineral resources,and the study area is a more favorable area for disposal bank site screening.This study is helpful for the characterization and prediction of the target surrounding rock space and potential uranium ore body,which provides an effective reference for the screening and evaluation of clay rock(mudstone)disposal sites,provides a solid scientific basis and data support for later decision-making and future work deployment,and then provides reference for subsequent research work,and plays a role in promoting the research process of clay rock(mudstone)geological disposal in China.At the same time,it provides a research basis for dealing with the relationship between the geological disposal of highlevel radioactive nuclear waste and uranium exploration,and the optimized deployment of uranium exploration in the research area.