Stress inversion studies using 3D seismic interpretation data and earthquakes focal mechanisms

Mohsen Gholami Dargahi¹ Shahrokh Pourbeyranvand²

1) Graduated student of Geophysics at KHwarazmi University
2) Assistant Professor of International Earthquake Engineering and Seismology

IOI Code : XBDG-DDFCG
Publication : The 6th national Congress On Civil Engineering, Architecture & Urban Development(6icsau.ir)
Abstract :
    Knowledge of stress field and how it changes, in addition to the fundamental importance in describing the geodynamics of the studied area, plays an important role in different branches of science such as geotechnics and geological engineering. Also tension studies in oil and gas reservoirs have been considered in the geomechanical framework of reservoirs. In this study, a new method of determining the slipping direction from interpreted 3D seismic data has been used for determining of paleostress field in one of the hydrocarbon fields in south of the Iran on different horizons with different geological age and nonlinear inversion of the momentary tensor has been used for estimation. Also the present state of stress field is calculated from the focal mechanism of earthquakes data in the above manner. The present state of stress due to the inversion of focal mechanisms and its comparison with the global stress map indicates that there is an acceptable correlation between the stresses obtained with regional stress approach. This study showed clockwise rotation in the direction of maximum horizontal stress over time, and the maximum horizontal orientation of the northwest-southeast in Cretaceous has become northeast-southwest in the present day.

Keywords : stress field non linear inversion 3d seismic data earthquakes focal mechanism