为评价修武盆地底—下寒武统荷塘组过成熟海相页岩储层特征,通过野外地质调查、有机地化分析、扫描电镜、比表面积以及等温吸附实验等手段对荷塘组页岩的储层特征进行了研究。分析结果表明,荷塘组页岩具有有机质丰度高、热演化程度偏高的有机地化特征;脆性矿物含量介于69.13%~78.56%之间,平均为75.16%,具有较好的可压裂性;储集空间类型以黏土矿物层间缝隙为主,次生溶蚀孔隙次之,孔隙结构以大孔为主,推测黏土矿物层间缝隙作出了主要的贡献,可能为主要的储气产所;吸附气量介于3.99~8.04 m~3/t,平均为6.02 m~3/t,具有较好的气体吸附能力。综上所述,下寒武统荷塘组页岩除热演化成熟度偏高之外,页岩气储层条件相对较好,具有较大的勘探潜力。
To evaluate the reservoir characteristics of over-mature marine shale of the bottom-lower Cambrian Hetang formation in Xiuwu Basin,the methods were used,including geological survey,organic geochemistry analysis,scanning electron microscope,specific surface area and isothermal adsorption. The results show that Hetang formation shale is characterized by high organic matter abundance and at a over-mature evolution stage. The brittle mineral content ranges from 69. 13% ~ 78. 56%,averaging 75. 16% with better capacity in hydraulic fracturing. The reservoir space types are composed of pores( cracks) between clay minerals and secondary dissolution pore and the pore structure is dominated by the macro-pore. It is speculated that the pores( cracks)between clay minerals make main contribution to the macro-pores and may serve as the gas storage. The gas adsorption content ranges from 3. 99 ~ 8. 04 m~3/t,averaging 6. 02 m~3/t with strong adsorption ability. Above all,Hetang formation shale owns better reservoir conditions and huge resource potential.