Review of petroleum exploration progress in passive marginal basins

Since the beginning of the 21st century, there has been a growing interest in passive marginal basins for global oil and gas exploration. According toexploration data statistics and advancements in theoretical and technological approaches, three keyaspects of sustained developmenthaveemerged. In terms of exploration theory, there has been a significant shiftfrom focusingsolely on rifts to the recent development of theories on sag-type and transform-type hydrocarbon accumulation in passive continental margin basins. This has led to theproposalof exploringoil in large sag margins, transform sag belts in passive continental margins, and the overlying far offshore turbidite sand in the mantle-exposed oceanic crust. Significant exploration breakthroughs have been achieved in the various regions, including the West African segment of the South Atlantic, the Southwest African segment, the eastern Mediterranean, both ends of the central and northern Atlantic, and the East African offshore areas. From an exploration perspective, there is a clear trend of horizontal development, moving from onshore to shallow water, deepwater, and ultra-deep water. Additionally,there is a vertical progression from slope channels to slope fans, base-of-slope fans, sub-salt carbonates, and deepwater fans.In terms of engineering technology, the development of deepwater drilling and seismic identification and characterization of sub-salt targets has greatly contributed to breakthroughs in drilling and exploration targets beyond a water depth of 3000m. Initially, exploration efforts onpassive continental margins were mainly focused on the Gulf of Mexico margins and the midsections of both sides of the South Atlantic. However, in recent years, exploration has gradually shifted towards the mid-northern Atlantic, the coast of East Africa, the Arctic, and other areas. In the future, the exploration for oil and gas in passive continental margins is expected to increasingly focus on far offshore ultra-deepwater, sub-salt, deep-sea, and polar regions. © 2024 Geological Society of China. All rights reserved.