摘要：

全球116个盆地157套富有机质页岩层系页岩油技术可采资源量约为2512亿吨,国外以海相页岩层系为主,国内以湖相页岩层系为主。页岩油富集层评价与岩相古地理分布密切相关,基于露头、岩心和地球物理的定量化数据是湖相页岩层系岩相古地理编图的基础; 时空尺度、单因素、理论模式是湖相页岩层系岩相古地理编图的核心要素。页岩纹层研究新进展为岩相古地理研究提供反映沉积环境的单因素及其表征方法,不同页岩纹层储集性和页岩油赋存状态差异大,以纹层组合和页岩微相进行编图是发展趋势。未来研究应针对湖相页岩层系岩相与有机质分布的非均质性特点,重点关注等时格架下的富有机质页岩分布规律、矿物—有机质复合颗粒的表征、标准化微相模式和沉积过程模拟与智能化编图等研究方向; 需结合现代沉积、沉积过程物理和数值模拟、有机岩石学和生物标志物等研究成果,重新认识湖相页岩层系沉积微相和有机质富集机理,建立符合细粒沉积物搬运—沉积规律、古地貌、生物演化特点的新沉积模式; 综合“反演”和“正演”方法,运用人工智能技术,结合页岩油甜点评价关键参数,开展不同类型纹层组合时空分布规律的定量化评价预测和智能化分析编图,精细刻画湖相页岩层系岩相古地理分布,指导页岩油富集区/段优选。

关键词: 湖相页岩层系, 细粒沉积岩, 岩相古地理, 陆相页岩沉积学, 页岩油

Abstract:

The global technically recoverable resources of shale oil are estimated at approximately 251.2 billion metric tons,derived from 157 organic-rich shale units across 116 basins. Internationally,shale oil exploration has largely focused on marine shale successions,whereas in China,lacustrine shales represent the primary target. The assessment of shale oil enrichment intervals is fundamentally governed by lithofacies palaeogeography. Lithofacies palaeogeographic reconstruction of lacustrine shale strata relies on quantitative datasets derived from outcrop,core,and geophysical analyses. Critical aspects of such reconstructions include considerations of temporal and spatial scales,single-factor analysis,and the application of conceptual depositional models. Recent progress in the study of shale laminae offers valuable single factors and diagnostic methods for interpreting depositional environments in palaeogeographic studies. Significant variations in reservoir properties and shale oil occurrence are observed among different lamina types. Consequently,palaeogeographic mapping based on lamina combinations and shale microfacies analysis represents an emerging research trend. Future research should aim to address the heterogeneous characteristics of lithofacies and organic matter distribution in lacustrine shale strata. Future studies should aim to resolve the heterogeneous distribution of lithofacies and organic matter in lacustrine shales,with priority given to: (1)delineating the spatial architecture of organic-rich shales within high-resolution chronostratigraphic frameworks,(2)characterizing mineral-organic composite structures,(3)establishing standardized microfacies classifications,and(4)developing depositional process simulations integrated with intelligent mapping techniques. An integrated approach combining modern sedimentological observations,sedimentary process simulations(both physical and numerical),organic petrology,and biomarker analysis is essential to reassess the sedimentary microfacies and organic enrichment mechanisms in lacustrine shale strata. This will facilitate the development of revised depositional models that accurately reflect the transport-deposition dynamics of fine-grained sediments,palaeotopographic constraints,and bioevolutionary context. By combining “inversion” and “forward modeling” methods and lever aging artificial intelligence technology,and incorporating key sweet-spot evaluation parameters,it is possible to quantitatively predict and intelligently map the spatiotemporal distribution of different lamina combinations. This methodology will allow for precise lithofacies palaeogeographic characterization of lacustrine shale strata and provide scientific guidance for the optimization of shale oil enrichment areas/layers.

Key words: lacustrine shale strata, fine-grained sedimentary rocks, lithofacies palaeogeography, non-marine shale sedimentology, shale oil

中图分类号: 

• P539.2