Photoelastic modeling of the tectonic stress field in the central part of the Bozhong depression

Abstract：Based on an intensive analysis of the sedimentary and tectonic evolution in the central part of the Bozhong depression, the paper reveals the characteristics of faults and their distribution in the area. A geological structural model of the central part of the Bozhong depression is constructed using E44-6101 type epoxy resin as matrix, maleic anhydride as a condensate and dibutyl phthalate C.P. as plasticizer, and experimental photoelastic modeling is performed for the tectonic stress field of the study area. Then the stress state and distribution of the nearly NNE-and nearly E-W-trending faults in the Neoid tectonic framework are reproduced. The experimental results show that under the action of the tectonic stress field petroleum usually migrates from the high-stress value zone to low-stress value zone and that the direction of the maximum principal compressional stress has been relatively stable in the Bozhong area since the Neogene. Based on an analysis of the experimental results, the paper discusses the characteristics of the NNE and nearly E-W sets of faults under the Neoid stress field and their controls on petroleum. As the Bozhong depression is China's major petroleum production area, the study of the distribution of the tectonic stress field of the basin can produce a basis for petroleum exploration and development of the basin