南川地区龙马溪组优质页岩段微观孔隙结构特征

Micro pore structure characteristics of high quality shale section of Longmaxi formation in Nanchuan area

为了分析南川地区龙马溪组优质页岩段孔隙纵向变化规律和平面展布特征,利用氩离子抛光+扫描电镜,结合有机碳、孔隙度、全岩、比表面积等实验分析测试数据等对南川地区JY194–3井、SY1井、NY1井等龙马溪组优质页岩储层的微观孔隙结构特征进行研究。结果表明,南川地区优质页岩储层孔隙主要为纳米级,以10.0~100.0 nm为主;页岩有机碳含量与孔隙度呈弱相关,石英含量与孔隙度呈正相关;纵向上随着深度的增加有机孔有先增多后减少的趋势,平面上有机孔隙发育程度由高到低依次为JY194–3井、SY1井、NY1井。

In order to analyze the vertical variation regularity and plane distribution characteristics of pores in Longmaxi formation high-quality shale section in Nanchuan area,the micro pore structure characteristics of high-quality shale reservoirs of Longmaxi formation such as JY194-3 well,SY1 well and NY1 well in Nanchuan area were studied by using argon ion polishing and scanning electron microscope combined with organic carbon,porosity,whole rock,specific surface area and other experimental analysis test data.The results show that the pores of high-quality shale reservoirs in Nanchuan area are mainly nano scale,mainly 10.0~100.0 nm;the organic carbon content of shale is weakly correlated with porosity,and the quartz content is positively correlated with porosity.In the longitudinal direction,the organic pores increased first and then decreased with the increase of depth.On the plane,the development of organic pores in well JY194-3 is better than that in well SY1 and NY1.