Study on modeling method of complex structure in Sichuan Shuangyushi Area based on unstructured grid

Based on unstructured grids，petrel software was used to build a geological model to propose a weakened intersection grid division method to optimize the geological structure model，and developed modeling methods for high and steep structures in complex structural areas，and explored the method of using geophysical data to analyze stratigraphic characteristics under complex structural conditions and effectively applied to the Sichuan Shuangyushi Area. The results show that the Shuangyushi Area of the Sichuan Basin has a series of nearly parallel fold-height structure groups spreading north，southeast，and west. The use of unstructured grids has a good effect on modeling high and steep structures，which intuitively and effectively explained the spatial distribution characteristics of faulted structures in the Shuangyushi Area，and it has a good effect on solving complex fold deformation and structural fitting in areas with developed faults. Using the attribute interpolation under the unstructured grid method，the complex fault model of triangulation was established，and the stratigraphic characteristics of the Maokou and Qixia Formations，the main target rock formations in the Shuangyushi Area were restored，and the method and combination characteristics of the fracture cutting strata were effectively restored. Regionally，the permeability and porosity models were combined to obtain the characteristics of the plane distribution of permeability and porosity in the Bishishi Area. The calculation results of the porosity and permeability models show that the overall permeability of the Shuangyushi Area is between 0.11% and 7.49%，and the average permeability is 2.09%; the porosity is between 0.01 and 1.052，and the average porosity is 0.26. Generally speaking，the permeability and porosity of Maokou Formation and Qixia Formation in Shuangyushi Area are relatively small and belong to tight rock formations. The porosity and permeability of rock formations in different regions vary to a certain extent. The permeability in the southwest is slightly higher than that in the northeast. The application of unstructured grids provides new research ideas for solving the effective characterization of geological features in complex structural areas，and has certain theoretical and practical significance.