致密岩油的研究进展、存在问题和发展趋势

Research progress,existing problem and development trend of tight rock oil

致密岩油是我国石油勘探比较现实的接替领域。致密岩油研究的难点在于:致密化过程与不同级别孔隙对石油迁移的影响,石油可否发生明显运移;是否全部为连续性油气聚集。近年来,人们总结出国内致密岩油的主要地质特征,初步探索了致密岩油的形成分布、富集成藏特征,逐步建立了纳米级孔喉的观测技术。国外研究认为,致密岩层内的流体流动受控于优势孔隙—喉道的分布,中孔网络与有机质内的大孔相连,提高了致密岩层的渗透性;致密油在富集过程中也会发生明显的侧向运移;连续性油气聚集模型不能准确反映威利斯顿盆地和大绿河盆地的油气资源潜力。今后应关注:岩石致密化过程和微米—纳米级孔喉的形成分布、致密岩油的赋存状态和运移成藏机理、我国致密岩油的资源潜力评价指标等3个关键科学问题。

Tight rock oil is a more realistic exploration domain of oil fields to succeed. The difficulties in tight rock oil research include the impact of tight process and different porosity classes on petroleum migration, whether petroleum has been transported or not, and whether all the reservoirs are continuous. In recent years, the main geologic features of domestic tight rock oil has been concluded, a prehminary discussion of the generation, distri- bution and accumulation of tight rock oil has been carried out, and an observation and measurement technique of nano-class pores has been established gradually. By contrast, the overseas researchers suggest that the fluid flow in tight rocks is controlled by the distribution of dominant pore-throat size. The networks of mesopores are ob- served to connect with large macropores within organic matter, which would obviously increase permeability in tight rocks. The obvious lateral migration of tight rock oil may take place during enrichment process. The model of continuous hydrocarbon accumulation could not evaluate accurately the resource potential in both the Williston Basin and the Greater Green River Basin. In near future, three crucial scientific problems should be focused on： rock tightening process and the relative distribution of miro- and nano- pore and throat structure, the occurrence state and migration and accumulation mechanisms of tight rock oil, as well as the evaluating indictors of resource potential of Chinese tight rock oil.