秘鲁Maranon盆地油气地质特征及勘探潜力分析

秘鲁Maranon盆地是安第斯山山前的前陆盆地之一。结合该盆地的勘探历史和勘探现状，对相关的钻井、物探以及地球化学等资料进行石油地质综合分析，评价了该盆地的石油地质条件及其勘探潜力。Maranon盆地内有三叠-侏罗系的Pucara组和白垩系的Chonta组两套主要烃源岩，分别于晚侏罗世和始新世开始成熟生烃。Pucara组生成的原油运移至该组地层的剥蚀面，充注至白垩系，但遭到后期造山运动的破坏，通过再次运移聚集成藏；Chonta组生成的原油向盆地东北部运移聚集成藏。盆地内的圈闭类型有背斜、断鼻、断块和地层圈闭等，可能发育多套储盖组合。Maranon盆地西部逆冲-前渊带和无古生界构造圈闭背景的白垩系圈闭、Pucara组碳酸盐岩圈闭以及白垩系Chonta组以下地层潜在的含油气圈闭是该盆地3个重要的潜力勘探领域。图4表1参24

Petroleum geological characteristics and exploration potential analysis of Maranon Basin, Peru

Maranon Basin is one of Sub-Andean foreland basins.With the basin's exploration history and current situation,drilling, seismic and geochemical data are analyzed to evaluate the petroleum geological factors and exploration potential.There are two sets of source rocks,Triassic-Jurassic Pucara and Cretaceous Chonta Formations.They began to be mature and expel hydrocarbons in the late Jurassic and Eocene.Hydrocarbons from the Pucara formation moved through unconformity towards Cretaceous formations,and re-accumulated after the Quechua tectonic movement.Hydrocarbons expelled from the Chonta Formation migrated toward the Northeast of the basin.Anticlinal,faulted and stratigraphic traps are commonly found in the basin.Three exploration targets exist in the basin: thrustfold-foredeep belt as well as Cretaceous reservoir without the background of hydrocarbon accumulation in Paleozoic;carbonate reservoir in the Pucara Formation;reservoir below the Chonta Formation.