Document Type : Original Research Paper

Authors

1 Department of Geology, Faculty of science, University of Birjand

2 , Department of Geology, Faculty of science, University of Birjand Birjan

3 National Iranian south oilfields company- ahvaz

Abstract

Image logs of 14 wells in Rag sefid anticline are showing 6 main fracture sets treanding N45, EW, N35, N100, N150 and N162 respectively. Development of fractures in the eastern part of the Rag sefid anticline, especially in the frontal edge, are in effect of the propagation fault related folding so that the most open longitudinal and cross axial fractures show N100 and N10 trends. Due to fold axis rotation 30 degrees to the north In the western part of the anticline the orientation of the fractures have changed and major fractures are longitudinal type and have N160 trend. In the middle and curved part of anticline NE-SW trend fracture sets are more developed by reactivation of hendijan basement fault. Convergence of stress axises as a result of the fault triple interaction In effect of Rag sefid thrust dipping to the north east and dextral shears dut to reactivation of hendijan and southern part of Izef basement faults caused the Restraining bend and dextral shear zone In the western part of the Rag sefid anticline. Creation of this shear zone caused clockwise rotation of anticline axis, rising more in northen west culmination on asmari top formation than southern east culmination, change in fractures orientation and also development and increase the density of fractures in the curved part of Rag sefid anticline.

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References
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