3D seismic interpretation and structural analysis of Z Field, eastern Persian Gulf

Abstract

Structural analysis of the Z hydrocarbon field in the eastern Persian Gulf is accomplished using 3D seismic data, which reveal a domed structure elongated in two axial directions. It is understood from underground contour maps that the axial trace of the structure changes from northwest in the north to northeast in the southern part of the structure. Faults affected by the Z structure also show change in their geometry and kinematics. Such structural attitude possibly took place with the early-formed salt diapir, which has sustained late strike-slip deformation. Some normal faults have reactivated as strike-slip faults, which means the arrangement of the strike-slip faults is likely influenced by preexisting normal faults. The geologic setting and particular geometry of the Z structure suggest the role of vertical movements of Precambrian Hormuz salt in the structure's development. Salt movements likely started in the Early Paleozoic and as a result of a releasing bend along a left-lateral strike-slip basement fault, which is in accordance with the earlier-detected basement lineament in the area. Late Cretaceous reactivation of this basement fault following the ophiolite obduction is responsible for strike-slip deformation and subsequent rotation of the domal structure.