The formation mechanisms of the hydrocarbonrich depressions in global deepwater areas
Author of the article:ZHANG Gongcheng1,2, FENG Congjun1, XU Jianyong2, LI Lin3, YAO Xingzong1, FENG Yangwei4, CHEN Ying2
Author's Workplace:1. Department of Geology, Northwest University, Xian, Shaanxi, 710069, China; 2. CNOOC Research Institute Co., Ltd., Beijing, 100028, China; 3. Southern Petroleum Exploration and Development Co., Ltd., Haikou, Hainan, 570216, China; 4. School of Geography and Tourism, Nanyang Normal University, Nanyang, Henan, 473061, China
Key Words:Deep-water areas; Oil and gas exploration; Reservoir combination; Hydrocarbon-rich depression; Basin
Abstract:
Since the beginning of the 21st century, the deep-water areas have become the main field for the
growth of global conventional oil and gas reserves, remaining in the early
stage of discovery with substantial exploration potential. Up to now,17 giant
and large petroliferous basins (or basin groups) with proven oil and gas
reserves exceeding 10×108 tons have been discovered in global deep-water areas. Their formation conditions constitute
the key scientific issues affecting and restricting deep-water oil and gas exploration. Based on the
comprehensive study of the distribution and formation conditions of the
discovered oil and gas fields in the global deep-water
areas, this paper proposes, for the first time, the “four
widespread elements” controlling the formation of deep-water giant and large petroliferous basins(group):“widespread
hydrocarbon source rock”,“widespread
high-quality reservoir”,“widespread effective cap” and “widespread large trap”. There are two major
fields of oil and gas exploration in global deep-water areas: new fields in the proven giant and
large petroliferous basins and potential giant and large petroliferous basins. The
new fields in the proven giant and large petroliferous basins mainly include
ultra-deep water areas, deep
layers, and shallow-layer
subtle traps, which represent the main exploration fields for the future.
Examples include deep sub-salt layers
in the Atlantic continental margin basin, Jurassic-Cretaceous clastic and carbonate rocks in the East
African continental margin, deep buried hills in the deep-water areas of the northern South China Sea, the
Triassic in the Barents Sea, sub-salt
Cretaceous clastic rocks and Jurassic reefs in the East Mediterranean, and deep
CarboniferousPermian in
the Bonaparte Basin on the northwest shelf of Australia. Given their low
exploration levels, these areas are key targets for near-term deep-water
exploration. The potential giant and large petroliferous basins, which may
already have oil and gas discoveries, drilled wells, or remained undrilled with
low exploration levels, share similar tectonic evolution processes and
petroleum geological conditions with the proven giant and large petroliferous
basins. These basins have significant resource potential and are new growth
points for future deep-water oil
and gas exploration.