摘要:
根据砂岩薄片、铸体薄片、扫描电镜、X-衍射分析,研究了鄂尔多斯盆地西峰油田镇北地区长3储层的成岩作用特征,认为该区长3储层处于晚成岩A期阶段,压实作用和胶结作用强烈地破坏了砂岩的原生孔隙结构,溶蚀作用和破裂作用则有效地改善了砂岩的孔隙结构。该区长3储层发育溶蚀作用相、压实作用相、胶结作用相和自生绿泥石胶结残余孔隙相,储层成岩相发育状况决定了孔隙结构的发育特征。发育次生孔隙相和残余孔隙相的砂岩具有较好的孔隙结构,孔渗较高;压实作用相和胶结作用相发育的砂岩具有很差的孔隙结构,孔渗很低。
Abstract:
Based on the data analysis of casting lamella, scan electron microscope and X-ray diffractions etc, the diagenesis include compaction, cementation, dissolution and fracturing, which belong to the “A” late diagenesis on Chang 3 reservoirs in Zhenbei area of oilfield in Ordos Basin. The compaction and cementation destroy the primary-texture of pore intensively, dissolution and fracturing change the pore structure effectively. The Chang 3 reservoirs in Zhenbei area develop dissolution facies, compaction facies, cementation facies and antigenic chlorite cementation residual pores facies, which impact the pore character of reservoirs. The sandstone develops secondary-pore facies and residual pores facies that have the better pore texture. The sandstone porosity and permeability are better; the pelitic impurity compaction facies and carbonate cementation facies develop in sandstone that have the lesser pore, so that the sandstone porosity and permeability are very poor in this area.