扎格罗斯盆地含油气系统分析与资源潜力评价

摘要

扎格罗斯盆地是全球常规油气资源最富集的前陆盆地。基于最新的数据资料，应用石油地质综合评价和含油气系统分析的方法，研究了扎格罗斯盆地的油气分布和主控因素，以成藏组合为评价单元，评估了油气待发现可采资源量，并探讨了盆地的油气资源潜力和未来的勘探领域。研究表明，盆地发育6套含油气系统，白垩系／古近系复合含油气系统、侏罗系含油气系统和志留系 Gakhum 含气系统是最重要的含油气系统。区域上，盆地的油气主要分布于迪兹富勒坳陷、基尔库克坳陷和胡齐斯坦隆起；层系上，油气主要储集于古近系、新近系和白垩系。油气分布整体表现为“坳陷富油、隆起富气”的特征，其油气富集的主要控制因素是优质区域盖层、有效烃源岩的展布和新近纪的构造运动。资源评价结果表明，扎格罗斯盆地待发现可采石油、天然气和凝析油的资源量分别为44.6×108 t、9.3×1012 m3和10.4×108 t，合计129.8×108 t 油当量，最有勘探潜力的成藏组合是二叠／三叠系 Deh Ram 群、Asmari 组和西北侏罗系成藏组合。%The Zagros Basin is the richest petroliferous foreland basin in the world.Based on the newest geolog-ical database,with an approach of integrated geological investigation and petroleum system analysis,this paper focuses on the oil and gas distribution patterns and the main controlling factors in the Zagros Basin and discusses the resource exploration potential in the future.Six petroleum systems are recognized,and the Cretaceous/Pa-leogene composite petroleum system,Jurassic petroleum system and the Silurian Gakhum petroleum system are of great significance.Regionally,the discovered oil and gas reserves are largely confined to the Dezful Embay-ment,Kirkuk Embayment and Khuzestan Uplift.Stratigraphically,they are mostly reservoired in the Paleogene, Neogene and Cretaceous.The distribution is characterized by patterns of oil in embayments and gas in uplifts. The controlling factors of the hydrocarbons in the Zagros Basin include the excellent regional cap rocks,the stra-tigraphic distribution of the effective source rocks and the Cenozoic tectonic movement.The results of petroleum resources assessment show that undiscovered oil,gas and condensate resources amount to 44.6 ×1 08 t,9.3 × 1 01 2 m3 and 1 0.4 ×1 08 t respectively in the Zagros Basin.This study proposes 3 favorable exploration plays:Permian /Triassic Deh Ram play of the Silurian Gakhum petroleum system,Asmari play of the Cretaceous/Pa-leogene composite petroleum system and Northwest Jurassic play of Jurassic petroleum system.