微生物碳酸盐岩孔隙研究进展

微生物碳酸盐岩不仅是研究古环境、古气候和地质历史事件的重要沉积记录，也是油气资源重要的储层类型之一。不同微生物群落的生理活动特性影响了原生孔隙的形成及保存，微生物沉积形成的不同尺度的沉积组构影响了孔隙的孔径大小及空间分布。微生物碳酸盐岩微相及共生岩性的微相组合型式对孔隙有效性及规模有重要影响，所处沉积地貌及相带使得微生物碳酸盐岩受海水-大气水成岩环境的胶结-溶蚀作用次序及程度不同，导致孔隙的非均质性。微生物相关的白云石化、胶结及岩溶等不同成岩作用，因其所处成岩阶段不同，而分别可能起到形成原生孔隙、保护残余孔隙及形成次生孔隙等不同效果，因而对孔隙形成及保存具有积极意义。微生物碳酸盐岩孔隙具有从纳米-亚微米级微孔隙到厘米甚至米级宏观孔隙等多个尺度，且与多尺度沉积结构构造有一定的耦合关系。因此，需要合理配置不同尺度样品的空间分布，运用多种方法技术表征不同尺度的孔隙，并增强各类数据的融合。此外，加强地质学科与地球物理学科的结合，是推动微生物碳酸盐岩油气储集层地质研究和勘探开发工作的重要途径。

Research Progress of Porosity in Microbial Carbonates

Microbial carbonates are not only important sedimentary records for paleo environments, paleoclimate and geological events, but also significant hydrocarbon reservoirs. Physiological characteristics of diverse microbial communities in part control the formation and preservation of primary pores, microbial depositional fabrics in various scales affect the diameter and distribution of pores. Combination patterns of microbial carbonates and associated facies have a great impact on usefulness and scale of pores. Different sedimentary processes and depositional environments of microbial carbonates affect sequences and degrees of cementation and dissolution during meteoric diagenesis, resulting in heterogeneity of pores. Microbe-related diageneses such as dolomitization, cementation, and karstification may form primary pores, protect residual pores and form secondary pores during various stages. Pore diameters of microbial carbonates are in range from nanometer-submicron level to centimeter and even meter level, which may correspond to multi-scale sedimentary structures to some extent. Therefore, it's necessary to analyze and characterize samples in various scales. In addition, the combination of geology and geophysics should be enhanced, being an important way to facilitate research of hydrocarbon reservoirs of microbial carbonates also benefit for the exploration and exploitation of oil and gas resources.