中马格达雷纳盆地地质特征与油气勘探有利区预测

Geologic characterisitcs and exploration favorable area predictions of middle Magdalena basin

基于广泛收集的数据资料,运用石油地质学的理论与方法,对中马格达雷纳盆地油气地质特征、油气富集规律进行分析,结果表明,晚白垩世La Lula组海相灰岩和泥页岩为主力烃源岩,新生界陆相砂岩为主要储集层,油气成藏组合为下生上储式,发育构造圈闭及复合圈闭;盆地油气主要富集于区域性古隆起、断裂和不整合上下的始新统-渐新统Chorros-Chuspas群砂岩中,断裂对油气藏的形成与分布起着重要的控制作用;盆地南部和东部边缘的逆冲褶皱带、中部隆起断裂带具有良好的勘探前景,同时西部斜坡的地层、岩性尖灭圈闭也具有较大勘探潜力。

Based on data collected from various sources and theories of petroleum geology,this paper analyzes petroleum geology characteristics and hydrocarbon enrichment regularities,and predicts the exploration favorable areas in the middle Magdalena basin.The marine limestone and mudstone of late Cretaceous La Luna formation is the major source rock,and the Cenozoic continental sandstone is the dominant reservoir.Therefore,the middle Magdalena basin mainly formed the hydrocarbon storage pattern as lower generation and upper accumulations.Structural traps and structural combination traps are widely developed in the basin.Oil and gas aremainly accumulated in the Eocene- Oligocene ChorrosChuspas group sandstones,which developed adjacent to regional paleo-highs,faults and unconformities.Faults are the principal factors that control the formation and distribution of hydrocarbon in the middle Magdalena basin.The over-thrust fault belt in the eastern and southern margin,unconformities in the west slope and central uplifts comprise the most promising areas. Meanwhile,the stratigraphic traps in the slope also have good exploration potential.