北部湾盆地迈陈凹陷东部物源方向及沉积体系时空演化

通过岩石薄片、铸体薄片、扫描电镜、粒度及物性分析等资料，总结了川东北地区须家河组储层的储集空间及孔隙结构特征，详细分析了须家河组储层经历的主要成岩作用类型，在此基础上定量计算并恢复了须家河组储层的孔隙演化过程。 研究表明：川东北地区须家河组储层处于中成岩阶段 B 亚期，对储层孔隙演化影响较大的主要有压实作用、胶结作用、溶蚀作用和构造破裂作用；砂岩储层原始孔隙度为 31.10%，其中 45.74%的原生粒间孔隙被压实而损失，22.51%的原生粒间孔隙被胶结充填而损失；溶蚀作用和构造破裂作用形成的次生溶孔和裂缝，使储层孔隙度增加至 6.4%，在一定程度上改善了低孔、特低渗砂岩储层的储集性能。 孔隙度定量计算结果与实测孔隙度一致，显示了该计算方法的准确性，对定量评价孔隙演化过程具有一定的指导意义。

Depositional system evolution and provenance orientation in the eastern Maichen Sag,Beibu Gulf Basin

Based on the data of rock slice, cast thin section, scanning electronic microscope, fractional and reservoir physical properties analysis, this paper summarized reservoir space and pore structure of Xujiahe Formation in northeast Sichuan Basin, analyzed the diagenesis types, and quantitatively calculated the pore evolution process. The research reveals that the reservoir of Xujiahe Formation is in the middle diagenetic B phase. The diagenesis includes compaction, cementation, dissolution and tectonic fracturing. The average original porosity is 31.1%. 45.74% pores are lost for compaction, and 22.51% pores are filled by cementation. However, the porosity was added to 6.4% because of dissolution and tectonic fracturing, which improved the reservoir quality in some degree. The result of calculated porosity is in accord with actual porosity, which shows the feasibility of this method, and it contributes directive meanings in the evaluation of diagenetic evolution.