海相页岩气储层特征研究进展与发展动态

富有机质泥页岩复杂的沉积成岩过程、细粒特征,以及远小于常规储层的以微米—纳米级为主的孔隙空间,给海相页岩气储层特征研究带来了极大的挑战。近年来借助多项先进技术方法的推广运用,在海相页岩气储层的多个方面形成了重要认识,页岩有机质与其成熟度关系密切,岩石矿物组分判定方法向定量化发展,岩相预测与建模技术得以应用,但成岩作用对储层的影响尚有待进一步探知,物性变化趋势的认识尚存在不同见解,孔隙结构实现了从定性到定量表征的跨越,页岩力学性质的解析能够有效指导压裂改造。通过进一步分析海相页岩气储层研究的发展动态,就页岩气储层孔隙结构系统表征、区域尺度上成岩与岩相变化的时空配置关系、成岩演化—岩相—孔隙系统—有机质丰度潜在的多元关系等研究方向作出了展望,以期推进储层特征研究在深度和广度上向前发展。

Reservoir Characteristics of Marine Gas Shales:Advances and Trends

The marine shale gas reservoirs bring great challenges in reservoir characterization due to complex depositional and diagenetic processes, and fine grain and much smaller pore size (from nanometer to micrometer). Reservoir characteristics of marine gas shales are considered as a key factor affecting the enrichment and resource abundance of shale gas. Recently, significant understanding have been achieved in organic matter characteristics, petrology, lithofacies, diagenesis, porosity and permeability, pore structure characterization and mechanical properties with the application of advanced techniques. Organic matter in shales is considered to be closely related to its maturity. The determination model of rock mineral components has been attempted to build quantitatively. The lithofacies prediction and 3D modeling techniques can be applied in shales. The diagenetic effects on shale reservoirs are required to be further explored. The understanding of the trend of porosity and permeability is still a challenge to be identified. The pore structure has recently allowed better characterization from qualitative to quantitative. The analysis of the mechanical properties of shales will help to guide the hydraulic fracturing strategies. Furthermore, the research trends and the development directions should be closely combined with the systematic characterization of pore architecture and networks in gas shales, and with the temporal and spatial configuration of diagenesis and lithofacies in regional scale, together with the intrinsic connections among diagenetic evolution, lithofacies, pore system, and organic matter abundances.