摘要
The present-day stress field of the Huanghua Depression is anlysized using finite element modeling(FEM).The models are constructed based on 3D seismic data,which consists of bottom surfaces of seven sequences and near-real spatial occurrences of faults in the depression.Comparing with the distribution of oil-gas reserviors and fault patterns around the area of the reservoirs,we quantitatively explain the distribution characteristics of the first/third principal stresses,stress intensity and direction of principal stresses.Then,the main factors influencing the structural features of the Huanghua Depression are discussed accordingly.The faults in the model are introduced as Coulomb-type frictional zones that refer to contact analysis of FEM.The results are as followed: 1) by adjusting the boundary conditions of the models,we find out that under the left-lateral shearing,the third principal stresses and the orientations of principal stresses show certain correlation with the position of five oil-gas reserviors and fault strikes in the Huanghua Depression,respectively.2) There are differences in the structural patterns and the directions of structural stress field of the the Huanghua Depression from north to south,which closely relate to the spatial occurrences of the Cangdong Fault,fault pattern,types and the spatial change of detachment fault.