阿根廷内乌肯盆地Vaca Muerta组页岩油地质特征与勘探开发潜力

Geological Characteristics and Exploration & Development Potential of Vaca Muerta Shale Oil, Neuquen Basin, Argentina

基于对阿根廷内乌肯盆地Vaca Muerta组页岩油成藏条件、富集特征、勘探开发历史、单井产量特征等因素的解剖,以及与北美页岩油气产区系统对比,认为Vaca Muerta组具有分布面积广、厚度大、地球化学指标优等特征,且成熟度相对适中,以页岩油聚集为主,又具有明显的超压特征,为一套优质的页岩油层。但由于Vaca Muerta组非均质性强,纵横向岩性变化大,能干层与软弱层间互分布,且石英含量总体偏低,碳酸盐矿物含量普遍超过40%,储层品质中等,在一定程度上将会影响压裂效果,岩石力学特征也将更加复杂。对于Vaca Muerta组,位于构造稳定带的井单井产量和EUR(估算最终可采储量)将明显高于走滑伸展断块内的井;推测位于凝析油气区的井EUR也将明显高于生油区的井。由于尚处于勘探开发的初期阶段,Vaca Muerta组钻井投资、单井产量和单井EUR指标均明显差于北美页岩油气产区,经济性偏差,但呈现出逐渐变好态势,后期仍存在较大的改善空间。阿根廷页岩油气开发目前仍面临政治、经济、原材料供给等一系列问题和困难,在低油价形势下商业性大规模开发尚待时日。

Based on the analysis of geological and accumulation characteristics, exploration & development history and single-well production of Vaca Muerta shale oil in the Neuquen Basin, Argentina, and the comparison with shale oil plays in North America, it is concluded that Vaca Muerta Formation is a set of high quality shale oil accumulation with wide distribution, large thickness, over pressure, good geochemical indexes, and moderate maturity. But its strong heterogeneity, big lithology change in vertical and lateral directions, intercalation of hard layers and weak layers, and lower quartz content, carbonate content of more than 40% in general, and medium reservoir quality would affect the fracturing effect to some extent, making the rock mechanics more complex. For the Vaca Muerta reservoir, the production and estimated ultimate recovery(EUR) of wells in structurally stable areas are significantly higher than those of wells in strike slip extensional areas, and it is inferred that the production of wells in condensate areas are higher than those of wells in oil generation areas. Still in the initial stage of exploration & development, Vaca Muerta Formation has much worse indexes of drilling cost, single-well production and EUR than North American shale oil plays. Its economical efficiency is poorer, but tends to be better through possible and proper treatments. The development of shale oil and gas in Argentina is still facing a series of challenges in aspects such as politics, economy, and supply of raw materials. Under the circumstances of low oil price, its commercial development will not be started for some time.