IDENTIFICATION OF THE MINOR FAULTS IN HUIMIN SAG AND PHYSICAL SIMULATION OF THEIR FORMATION MECHANISM

On the basis of high-precision 3D seismic data, through signal enhancement, large-scale display and ant body tracking technology, the identification marks of minor faults on section are established as follows:1) slight misalignment of co-phase axis; 2) bifurcation and merging of cophase axis; 3) deflection and strong phase conversion of co-phase axis; 4) reflection disorder or blank band; 5) sudden increase/decrease/disappearance of co-phase axis, abrupt change of wave group interval, showing discontinuity; and 6) using ant algorithm seismic profiles. By analyzing the spatial combination styles of different-scale faults in Linbei area, the evolution processes are restored based on the principle of balanced section. The physical simulation shows that the minor faults are the derivative or associated structures of the major fault activity, which are mainly caused by the regional stress field near the major fault, mostly parallel to the major fault and distributed in parallel.