Abstract:

Elastic-plastic incremental modeling of tectonic stress field is to approximate parabolic stress-strain curves with several linear portions and perform elastic modeling with finite element method in each linear portion. It is applied to perform numerical simulation of the tectonic stress field in T₃x^2-4 strata in Xiaoquan-Xinchang area.Modeling results show that structural fractures are poorly developed in this area,except in the near-fault regions where regional structural fractures are relatively well developed. Seismic section interpretation and structural evolution analysis reveal that the main fractured zones are good hydrocarbon migration pathways and no serious leakage of hydrocarbons exists.Therefore,favorable regions for gas exploration are those neighboring faults,especially the near E-W trending faults which are parallel with the current major stress and in open state can more effectively conduct gas.

Key words: tectonic stress field, elastic-plastic incremental method, structural fracture, petroleum exploration