古地理学报2025，Vol.27Issue(5)：1137-1156,20.DOI:10.7605/gdlxb.2025.056
基于有机质孔特征的页岩储集层评价研究:以川南地区五峰组—龙马溪组为例
Evaluation of shale reservoirs based on organic pore characteristics:a case study of the Wufeng and Longmaxi formations in southern Sichuan Basin
摘要
Abstract
Organic matter pores serve as the primary spaces for shale gas enrichment and accumulation,and their developmental characteristics are crucial for reservoir evaluation and selection.However,current research on the combinations,characteristics,and heterogeneity of mineral-organic matter pores remains relatively limited.This study focuses on the Longmaxi Formation and Wufeng Formation shales in the southern Sichuan Basin region,employing a suite of techniques including whole-rock X-ray diffraction analysis,argon ion polishing-scanning electron microscopy,electron micro-probe analysis,cathodoluminescence,and Image J image analysis.These methods are used to elucidate the relationships between minerals and organic matter,describe the structural characteristics of mineral-organic matter pore combinations,analyze the distribution patterns of these combinations across different lithofacies,and investigate the impact of their heterogeneous distribution on shale reservoir properties.The results reveal the following key findings:(1)Quartz,clay minerals,carbonate minerals,and pyrite exhibit multiple occurrence relationships with organic matter in shale,and a total of four categories comprising 12 types of mineral-organic matter pore combinations were identified;(2)The distribution of mineral-organic matter pore combinations varies among different lithofacies.Biogenic siliceous shale is predominantly characterized by quartz-organic matter pore combinations,with a relative content of 73.59％.Clay shale,feldspathic-calcareous siltstone,calcareous shale,and feldspathic siltstone are mainly dominated by clay mineral-organic matter pore combinations,with relative contents of 73.45％,55.45％,38.92％,and 53.66％,respectively.Calcareous siltstone is primarily characterized by carbonate mineral-organic matter pore combinations,with a relative content of 55.01％;(3)Organic matter encapsulated within quartz and clay minerals exhibits a flow structure,characterized by high organic matter content,large pore size,high porosity,and good pore connectivity.These pore types are the most favorable for reservoir development;(4)Biogenic siliceous shale is identified as the optimal shale gas reservoir,and its high gas content(3.53 m3/t)aligns closely with the high relative abundance(33.71％)of favorable mineral-organic matter pore combinations.In conclusion,the distribution characteristics of mineral-organic matter pore combinations significantly influence the gas content of shale,and the relative content of favorable pore combinations is positively correlated with gas content.This finding holds substantial implications for the evaluation and selection of shale gas reservoirs.关键词
五峰组—龙马溪组/矿物-有机质孔组合/页岩储集层/岩相/非均质性/页岩气富集Key words
Wufeng and Longmaxi formations/mineral-organic matter pore combination/shale reservoir/lithofacies/heterogeneity/shale gas enrichment分类
能源科技引用本文复制引用
唐晴,梁超,吴靖,籍士超,谢浩然,赵梓龙..基于有机质孔特征的页岩储集层评价研究:以川南地区五峰组—龙马溪组为例[J].古地理学报,2025,27(5):1137-1156,20.基金项目
国家自然科学基金(编号:42172165)、泰山学者计划(编号:TSQN202306208)、山东省高等学校青年创新团队(编号:2022KJ215)联合资助.[Co-funded by the National Natural Science Foundation of China(No.42172165),the Taishan Scholars Program(No.TSQN202306208),and the Youth Innovation Team of Higher Education in Shandong Province,China(No.2022KJ215)] （编号:42172165）
