Petroleum Geology in the NC41 Area (Western Libyan Offshore)

The NC41 area belongs to a polyphasic pull-apart basin in the western side of the Libyan offshore. The early stage of the basin was upper Cretaceous in age. The local troughs of the pull-apart were affected by restricted conditions that gave origin to the cretaceous source-rock (Kef Fm.). The deposition of the cretaceous source is a peculiar feature of the deepest part of the Sabratah-Misrata basin. The geochemical properties and evolution of the cretaceous source led to the generation of gas that largely contributed to most important accumulation of the area. The trap-forming processes started during the late Cretaceous transpressional phase. The early faults were reactivated later, sometime evolving into attractive exploration features. The present structural style, characterized by faulted anticlines, results in particular from late Cretaceous and Oligocene events. The two major exploration plays are the Eocene shallow-water carbonates and the Cretaceous carbonate platform. The former is the most successful play of the area. The latter is presently largely unexplored in spite of the close concurrence of effective source and reservoir units but it shall represent a challenging target for next future exploration.