南美重点盆地油气地质特征及资源潜力

摘要

按区域地质—盆地—含油气系统—成藏组合的研究思路,总结了南美地区不同类型盆地的油气成藏特征和富集规律,评价重点盆地资源潜力.研究认为,南美洲大陆受大西洋、太平洋的"开"、"合"区域构造作用的控制,造就了东、西、南、北不同构造位置(盆地)构造演化特征的不同,发育了克拉通、裂谷、被动大陆边缘和前陆等4类主要的原型盆地.平面上,油气主要分布于安第斯弧后的前陆盆地群和大西洋西岸的被动大陆边缘盆地群,已发现油气储量分别占80.4%和14.7%;层系上,主要分布在中、新生界;发育砂岩和碳酸盐岩两大类储集层,以前者为主.在地质综合评价的基础上,以成藏组合为评价单元,完成了9个重点盆地34个成藏组合待发现资源量定量计算评价,优选了Ⅰ、Ⅱ类有利成藏组合.%Hydrocarbon enrichment and accumulation in different types of basins in South America were studied from the perspectives of regional geology,basin,petroleum system to play,and their resource potentials were esti?mated. Basins in different parts of South America have different tectonic evolution features due to the expanding and closing of the Atlantic and Pacific oceans.Four basin types developed:craton,rift,passive continental margin and foreland basins. Oil and gas mainly accumulated in the Andean foreland basins and the passive continental margin basins on the Atlantic coast,accounting for 80.4% and 14.7% of the discovered hydrocarbon,respectively. Stratigraphically,most oil and gas accumulated in the Mesozoic and Cenozoic sandstone and carbonate reservoirs, especially in sandstones. On the basis of comprehensive geological evaluation, the undiscovered resources of 34 plays in 9 major basins were calculated,and subsequently the first two prospective plays were identified.