论文部分内容阅读
致密油已成为全球石油地质领域研究的一大热点,在中国的很多盆地也发现了致密油分布。通过对国内外大量文献资料的调研,总结致密油的地质研究现状。结果表明致密油聚集条件与常规油藏成藏有明显区别,可主要概括为3点:1广覆式分布的优质生油层;2大面积分布的致密储集层;3连续型分布的储集层与生油岩紧密接触的共生层系。致密储层孔隙系统主要为微米—纳米孔喉系统,并以纳米级孔喉为主。致密油聚集需要强大的源储剩余压差以克服纳米孔喉系统形成的强大的毛细管阻力。致密油聚集以初次运移为主,只发生短距离二次运移,这种运移具有非达西流特征。目前对致密油的充注、运移和聚集的研究还不够深入,致密储层非均质性及源储压差演化等因素对致密油聚集的影响尚未被揭示,这些问题都需要进一步深入探讨。对今后致密油的研究,建议关注致密储层微观孔喉结构分布的非均质性及对石油储集的有效性、石油充注机理及储层非均质性与致密油富集的耦合关系等科学问题。
Tight oil has become a hot spot in the global field of petroleum geology. In many basins in China, tight oil distribution has also been found. Through a large number of domestic and foreign literature research, summarize the status of tight oil geological research. The results show that the tight oil accumulation conditions are obviously different from the conventional oil accumulation, which can be summarized as follows: 1 high-quality oil-bearing formation with broadly distributed distribution; 2 large-area dense accumulation reservoirs; 3 continuous-type distribution reservoirs The symbiotic strata are in close contact with the source rock. The main pore system of the tight reservoir is the micropore-nanopore throat system, which is dominated by nano-pore throats. Tight oil accumulation requires a strong residual pressure across the source reservoir to overcome the strong capillary resistance created by the nanopore throat system. The tight oil accumulation mainly relies on primary migration, but only secondary migration occurs at short distance. This migration has non-Darcy flow characteristics. At present, the research on the filling, migration and accumulation of tight oil is still not deep enough. The influence of tight reservoir heterogeneity and evolution of source-reservoir pressure difference on the accumulation of tight oil has not yet been revealed, and these problems need to be further explored . For the study of tight oil in the future, it is suggested to pay attention to the heterogeneity of micro-pore-throat structure distribution in tight reservoirs and their effectiveness on petroleum storage, the mechanism of oil filling, and the coupling between reservoir heterogeneity and tight oil enrichment And other scientific issues.