3D seismic model of faulting systems of a Jurassic - Cretaceous sedimentary packages in Merjan_West Kifl Oil fields - Central Iraq

Abstract

Study of three dimension seismic data of Merjan survey, central Iraq has showed that the Jurassic – Cretaceous succession is affected by faulting system. Seven major normal faults were identified and mapped. Synthetic traces calculated from sonic and density logs of the well Me-1. Two exploration wells were drilled in the area Me-1 and Wkf-1 wells. The area is characterized by extension phase led to graben system forms rift sub-basin. The structural components of rift sub-basin has identified and visualized in three dimensions. Discussion about the effect of this system on the sedimentary package has been presented. Faulting framework can be divided into two groups: the first affects the Jurassic and lower Cretaceous rocks and the second affects the upper Cretaceous and lower Tertiary rocks. The first group is associated with the post rift thermal sag, passive margin progradation and gravitational collapse (lower Jurassic – mid Turonian 190–92 ma); approximately during the Sargelu – NahrUmr depositional time. The second group is limited and is associated with the rifting creating the Euphrates graben as collision wanes (Late Turonian – Maastrichtian 90–70 Ma) approximately during the Tanuma shale/Sadi – Shiranish depositional time.