Research on Fault Stability in Junggar Basin Based on 3D Geological Modeling

Abstract

The distribution characteristics of ground stress and fault stability are very important for horizontal well location deployment, drilling orientation and hydraulic fracturing design in complex areas. The Junggar basin is characterized by intense structure and complex strati-graphic characteristics, so it is necessary to clarify the variation law of ground stress, identify fault stability and control drilling risk to improve drilling efficiency. Based on the data of regional geological structure and earthquake, this paper selects the calculation model of ground stress and carries out 3D geomechanical modeling. Through the model calculation, the magnitude and characteristics of regional ground stress are obtained, and the regional characteristics are judged to be the transition from strike-slip fault control to normal fault control. Based on the simulation results, three key strata are studied, and the influence of faults on the variation of ground stress is analyzed. The Coulomb failure function is used to make mechanical discrimination of five main faults in the study area, and the analysis shows that F1 and F3 faults are in a stable state, while F2, F4 and F5 faults are currently in an unstable state. This judgment result is conducive to timely warning of drilling risks. Through systematic geomechanical modeling and fault stability analysis, this study provides important theoretical support for related engineering in complex areas, and can effectively improve drilling efficiency.

Keywords

• log interpretation
• crustal stress
• 3d geomechanical modeling
• fault stability
• model calculation
• junggar basin