Current Stress Field Simulation Of Shunbei 5 Fault Zone

The study of in-situ stress is of great significance to oil and gas engineering,and the distribution characteristics of in-situ stress are the basis of reservoir reconstruction.Ordovician reservoir in Shunbei area is a fracture cave type reservoir controlled by fault zone,which needs to be fractured and reformed.However,the current distribution characteristics of stress field in Shunbei main fault zone are not clear,which restricts the reservoir reformation.In this paper,Shunbei 5 fault zone is taken as the research object.On the basis of geological modeling,the current stress direction and current stress test results of the region are taken as the boundary conditions,and the rock mechanical parameters of the model are given by the rock physical test report.The current stress field distribution characteristics near Shunbei 5 fault zone are studied by numerical simulation method.The result shows that the maximum principal stress in the north section of Shunbei 5 fault zone is 185MPa?195MPa,the direction is vertical,the middle principal stress is 160MPa?180MPa,the direction is NE-SW trending,the minimum principal stress is 125MPa?145MPa,and the direction is NW-SE trending.The maximum principal stress in the middle section of Shunbei 5 fault zone is185MPa?195MPa,the direction is vertical,the middle principal stress is 165MPa?175MPa,the direction is NE-SW trending,the minimum principal stress direction is130MPa?140MPa,and the direction is NW-SE trending.The triaxial stress is smaller in the fault zone and larger near the fault zone.The horizontal maximum principal stress direction will deflect near the fault zone,and the closer the distance to the fault zone,the greater the degree of deflection.The present stress field is mainly affected by the shape,scale and quantity of pre-existing faults,which mainly shows that the overall triaxial principal stress is smaller,and the range of stress anomaly is slightly different,which is 2?6 times of the width of the fault zone as a whole,the compression section is the largest,the tension section is the second,and the translation section is the smallest.By using the present stress direction,the propagation rule of artificial fracture can be defined,and the opening trend of natural fracture can be judged,which provides the basis for reservoir reconstruction.