Construction Of Complex Multi Constrained Geological Surface Based On GPU Parallel Computing

Spatial reconstruction and expression of complex geological surfaces is the core foundation of structural interpretation and geological mapping, the method of geological surface reconstruction and expression directly determines the efficiency, effectiveness and practicability of the software system. For the common geological structure, the traditional methods such as Kriging interpolation or Delaunay triangulation can be used to reconstruct the surface, which can use rectangular or triangular meshes to express the surface.With the constant deepening development degree of prospecting,the fault block Under complicated geological conditions has gradually become an important position in increasing oil production.How to implement the complex fault block structure is the main task of the current structural interpretation.So the spatial reconstruction and expression of geological surfaces under complex geological conditions has a very important significance.Under the complex geological conditions, especially in fault(including normal faults and reverse faults),the strata broken badly,using traditional meshing method to reconstruct and express stratum interface correctly,there is a considerable difficulty especially in the irregular layer data(two dimensional measuring line) and multiple-valued layer data(layer of overthrust), the traditional method is powerless.Therefore, there is an urgent need to study new method for surface reconstruction and expression,this paper based on the latest research field of computational geometry and the latest geological research results where from the domestic and foreign.Based on partial differential equation,using the characteristics of rectangular and triangular meshes,constructing smooth surface in Complex Multi-Constrained geological space,specific work is as follows:Based on rectangular mesh generation method,construct fault conditions from the initial layer data,use the structure of rectangular mesh,solving partial differential equations by finite difference schemes, take the geological fault polygon a s the internal boundary condition of the surface,then apply the three different order partial differential equations to the actual exploration data of a seismic area,and analyze the stability and feasibility and the superiority of surface,the constructed surfaces with the three equations can achieve a certain degree of smoothness,we constructed three surfaces with different characteristics to meet the requirements of the reconstruction of surfaces under complex geological conditions, achieved the requirement of the variety of surface,the requirements for the complexity of surface reconstruction are enriched.But for large work area, especially the basin level work area,because the very large amount of data,which lead to the iterative calculation of partial differential equations is very slow,through the division of large and small grid,the calculation of partial differential equation is carried out independently in each small grid,the attribute values of grid points close to the true value,then take a iterati ve computation for the the global data,this can shorten time of the surface construction,also can use multi thread technology on large and small grid blocks,further shorten the time of surface reconstruction,At last, GPU parallel computation is carried out on the block grid, and the iterative speed of partial differential equations can be improved by the GPU's strong floating point computing power, so as to improve the speed of surface reconstruction.In order to meet the requirements of arbitrary topology of geologic faults,take the fault data of work area into constrained Delaunay triangulation,using the finite element method to solve the reconstructive mean curvature flow equation on triangular mesh, construct the discretization scheme of the reconstruct ive mean curvature flow on the triangular mesh,then get the steady state solution of the equation by the iteration termination condition,reconstruct the complex multi constrained smooth surfaces on the triangular mesh based on finite element method,although finite element method involves a large number of dense operational matrix and infinitesimal calculus,the iteration time is much slower than the finite difference method,but is more stable than the finite difference method, allowing fewer iterations to complete the solution of the linear system.In this paper, based on the actual investigation of the work area data, has reconstructed the smooth surface, and greatly reduces the time of surface reconstruction, realized the fault with complex multi constraint surface for rapid construction, is expected to in the geological field spread more in-depth research and application.The fast construction of complex multi constrained surface with fault is realized. And expected to expand more in-depth research and application in the geological field.