富有机质泥页岩微纳米孔隙系统演化特征及模式研究新进展

富有机质泥页岩孔隙系统演化特征及其模式的研究有助于完善页岩油气微纳米储层地质理论,进一步揭示页岩油气富集成藏机理,并促进页岩油气综合地质评价与勘探开发.通过综述富有机质泥页岩孔隙系统特征及发育演化影响因素,简述了泥页岩复杂孔隙系统研究发展历程,分析了自然成熟序列泥页岩和模拟序列泥页岩孔隙系统演化特征,总结了国内外富有机...

New Research Progress on Organic-rich Shale Micro- and Nanoscale Pore System Evolution Characteristics and Models

Research on evolution characteristics and models of organic-rich shale pore system are helpful for improving shale oil and gas micro- and nanoscale reservoir geological theory， to further reveal shale oil and gas enrichment and accumulation mechanisms， and to promote overall shale oil and gas geological evaluation， exploration and development. This study reviews the pore system characteristics and the factors affecting the evolution of organic-rich shale. The research and development history of the complex pore system in shale are briefly described， and the pore system evolution characteristics of natural and simulated matured shale are analyzed. The pore system evolution models of organic-rich shale in China and elsewhere are summarized， and the prospect of the current research situation of pore system is put forward. Due to the small pore size， poor connectivity and dense structure of organic-rich shale， the pores are more difficult than the conventional oil and gas reservoir to classify and identify. They are commonly found in quartz， feldspar， calcite， clay minerals， etc.， and may be also formed in organic matter. Research on complex shale pore systems have gone through the stages of scientific exploration， theoretical formation and practical development. The development of micro- and nanoscale pores is controlled by both thermal mature hydrocarbon generation and diagenesis， and their formation and evolution are also affected by both internal and external factors. Among the external factors， the sedimentary environment and structural background jointly determine the basic conditions for the development of shale micro- and nanoscale pore systems. Of the internal influencing factors， lithological change and mineral composition influence fracturing properties and pore structure characteristics of shale， both of which will cause the pore space in shale increase or decrease to a certain extent. TOC content and kerogen type affect pore volume and surface area of organic matter， while the thermal maturity of organic matter restricts the evolution trend of different pore types. There is no simple positive or negative correlation between thermal maturity and the pores in a shale reservoir， and there is also considerable disagreement about the cause of nanopore variation with change of thermal maturity. This paper also reviews the progress and current status of research into pore system evolution in natural and simulated matured shale， and summarizes the typical evolution models of pore system in natural and simulated matured shale， analyzing the main influencing factors in the evolution process of these pore systems. It is believed that samples of different types of organic matter and from different depositional environments should be selected for deeper research. The qualitative and quantitative analysis of the main controlling factors and evolution of organic-rich shale should be strengthened. Simulated systems and simulation experiment conditions need to be improved to make them much more similar to actual geological conditions. The accuracy and range of measuring micro- and nanoscale pore systems with different maturity sequences should be improved.