哥伦比亚东南部Caguan-Putumayo盆地油气勘探潜力分析

Analysis of hydrocarbon exploration potential in Caguan-Putumayo Basin,in Colombia

哥伦比亚东南部的Caguan-Putumayo盆地是安第斯山前的弧后前陆盆地,在Putumayo盆地南部地区发现了大量的油气资源,但是Putumayo东北部和Caguan盆地勘探程度较低,属于风险探区,为了挖掘该地区的油气资源,需要加强该地区的石油地质和地球物理研究.本文综合利用该地区现有的地质和地球物理资料,结合地震、钻井、地化分析等资料,基于盆地模拟基础理论,系统分析了Caguan-Putumayo盆地的构造演化历史、有机质生烃潜力、储层展布特征和油气成藏模式.研究结果表明:Caguan-Putumay普遍发育Pepino/Mirador和Cretacous两套储层,由安第斯山前带向东北和东南方向逐渐抬升、减薄;Caguan地区烃源岩生烃条件较差,没有有效的烃源岩生烃,以构造-岩性油气藏为主;Putumayo地区白垩统烃源岩具有较好的生烃条件,以构造圈闭和地层-岩性油气藏为主.通过对Caguan-Putumayo盆地的系统分析,为该地区的油气风险勘探提供理论支持.

Caguan-Putumayo basin located at the southeastern of Colombia,is a typical pre-Andean arc foreland basin.In the south part of Putumayo,where has found quantity oil and gas resources,but in the northeast of Putumayo and Caguan,has high risk with less geological and geophysical data.So it is very important to enhance the regional petroleum geology and geophysics＇ research for the oil and gas exploration.In this paper,based on basin modeling ideology,using the less geological and geophysical data（such as seismic,drilling,geochemical data,etc）,we systematic analysis the basin＇s tectonic evolution history,hydrocarbon generation condition,reservoir distribution feature and accumulation mode.The result shows that the main reservoirs,such as Pepino／Mirador and Cretaceous,uplifting and thinning from southwest to northeast and southeast.In Caguan,the source rock with poor generation condition,not matured,belong to structurallithologic reservoir.In Putumayo,Cretaceous source rocks（Caballos Villita）have good generation conditions,with structural stratigraphic and lithologic traps.Based on basin modeling ideology,using the comprehensive geological and geophysical research method,we systematically analysis the regional exploration potential and support the future petroleum exploration activity.