Three-dimensional Geological Body Finite Element Mesh Modeling Method Research

Three-dimensional geological modeling is widely used in all phases of petroleum development.In the field of petroleum exploitation,the data information is very complex,and the establishment of 3D geological model can reflect the subsurface geological structure more intuitively,thus helping the staff to better understand and judge the complex geological conditions,and then make the best petroleum exploitation plan in a more targeted way.The purpose of this paper is to discuss in depth the key technologies and methods in the process of subsurface space reconstruction,based on complex geological 3D point data,focusing on fault triangulation network reconstruction,stratigraphic triangulation network reconstruction and surface modeling techniques.After several experiments to ensure the feasibility of the modeling method and apply it to specific engineering cases,the specific implementation are as follows:1)In view of the characteristics of subsurface distribution of faults and strata,the research of 3D triangle network construction method based on 2D Delaunay idea was carried out,and the constraints of angle,line and surface were introduced;secondly,the 3D triangle collision test was carried out to complete the overall construction network of faults and strata on the basis of ensuring the true reflection of subsurface space distribution,and then the feasibility of the triangle network construction method was verified.2)By studying the reconstruction method of geologic body model under surface modeling theory,automatic,fast and efficient Delaunay tetrahedral mesh dissection based on the enclosing box model is realized.Firstly,a suitable enclosing box range is selected and the enclosing box cutting algorithm is applied to the triangular mesh model of the geological layer obtained in(1)above,and then Tet Gen is invoked and given its adjustment parameters to tetrahedrally mesh the obtained closed geological body model,and finally the 3D model of faults and strata under surface modeling is obtained.