Abstract: Fractured reservoir is one of the main types of Carbonate reservoirs in Tazhong area, which controls the petroleum productivity of the Ordovician. Based on the related geological data, the present tectonic stress filed of Ordovician is simulated using 3D finite element method. The fracture-developed zones of Middle-Lower and Upper Ordovician in Tazhong area are predicted with Griffth's rupture criterion. The statistical fracture linear density of single well and the locations of oil-gas wells testify that the tectonic fracture zones predicted by using 3D finite element method basically agree with the actual fracture areas in Tazhong. It also shows that the oil-gas reservoirs are mostly located in areas with high tectonic stress fields.

Key words: stress field, finite element, numerical simulation, fracture linear density, Tazhong area