四川盆地焦石坝地区页岩气差异富集机理研究

Mechanisms for differential gas enrichment have become the key scientific question for shale gas exploration and development in the China. The exploration results show that high-maturity marine organic-rich shales in the Jiaoshiba area of Sichuan Basin display distinctly differences in porosities, pressure states and hydrocarbon gas contents. The Jiaoshiba area is a natural laboratory to study the differential enrichment of shale gas. In this project, based on the systematic comparing of organic-rich shales with different mineral compositions, different pressure regimes and different gas content, we try (1): to reveal the evolution of pores and fractures and its majors controlling factors in different organic-rich shale types; (2) to study the evolution of pressure and stress and its relationships with the enrichment and depletion of shale gas; and (3) to illustrate the preservation conditions of shale gas by shale gas content, occurrence attitude, and geochemical behavior. This study could reveal the mechanisms for differential gas enrichment in the Jiaoshiba area and would provide important scientific bases and models for prediction and assessment of shale gas exploration potentials in China.

页岩气差异富集机理成为制约我国页岩气勘探开发的核心科学问题。焦石坝地区页岩气勘探成果表明该地区富有机质页岩的孔隙度、压力状态和含气性存在明显差异，是研究页岩气差异富集机理的天然实验室。本课题基于焦石坝地区不同类型、不同含气性富有机质页岩的系统对比，研究①富有机质页岩孔隙-裂隙演化及其控制因素；②富有机质页岩压力-应力发育演化及其与页岩气富集和贫化的关系；③富有机质页岩含气性、赋存状态、地球化学特征及其与页岩气保存条件的关系，旨在揭示焦石坝地区页岩气差异富集机理，为我国复杂地质条件下页岩气勘探潜力预测和评价提供科学依据和模型。

页岩气差异富集机理是制约我国页岩气勘探开发的核心科学问题。焦石坝地区页岩气勘探成果表明该地区富有机质页岩的孔隙度、压力状态和含气性存在明显差异，是研究页岩气差异富集机理的天然实验室。本项目以焦石坝地区页岩气富集机理与有效勘探开发为出发点，开展不同类型、不同含气性富有机质页岩的系统对比，取得了一定的研究进展。明确了富有机质页岩多尺度非均质性及其对页岩储层物性的影响。建立了富有机质页岩储层孔隙-微裂缝联合表征方法，明确了不同类型富有机质页岩孔隙发育特征及其控制因素。建立了页岩和顶底板在不同构造应力场环境的破裂方式和先后顺序，明确了页岩系统封闭性与页岩气富集程度的关系。依托本项目共发表论文25篇，其中第一作者和通讯作者SCI论文16篇、EI论文2篇，2篇入选ESI高被引论文。