石油勘探与开发2018，Vol.45Issue(2)：223-234,12.DOI:10.11698/PED.2018.02.05
致密砂岩储集层微观结构特征及成因分析——以鄂尔多斯盆地陇东地区长6段和长8段为例
Micro pore and throat characteristics and origin of tight sandstone reservoirs: A case study of the Triassic Chang 6 and Chang 8 members in Longdong area, Ordos Basin, NW China
摘要
Abstract
The microstmcture differences of the Triassic Chang 6 and Chang 8 members tight reservoirs in the Longdong area of Ordos Basin were compared by means of cast thin sections,scanning electron microscope,X-ray diffraction,and constant rate mercury injection.Their pore evolution models were established,and the effects of main diagenesis on densification were examined.The throat is the main factor controlling the physical properties of the Chang 6 and Chang 8 members reservoirs:The lower the permeability,the smaller and the more concentrated the throat radius and the larger the proportion of the throats in the effective storage space.There are several obvious differences between Chang 6 and Chang 8 members:(1) with the increase of permeability,the contribution of the relative large throats to the permeability in the Chang 8 member reservoir is more than that in the Chang 6 member reservoir;(2) the control effect on pore-throat ratio of the nano-throats in the Chang 6 member reservoir is more significant.The sedimentary action determines the primary pore structure of the Chang 6 and Chang 8 members sand bodies,and the diagenesis is the main factor controlling the densification of the reservoirs.Because of the difference in rock fabrics and the chlorite content of Chang 6 and Chang 8,the strong compaction resulted in less porosity reduction (17％) of the Chang 81 reservoir with larger buried depth and larger ground temperature than the Chang 63 reservoir (19％).The siliceous,calcareous and clay minerals cement filling the pores and blocking the pore throat,which is the key factor causing the big differences between the reservoir permeability of Chang 6 and Chang 8 members.关键词
鄂尔多斯盆地/三叠系/延长组/致密砂岩储集层/恒速压汞/微观孔喉结构Key words
Ordos Basin/Triassic/Yanchang Formation/tight sandstone reservoir/constant-speed mercury intrusion/micro pore and throat structure分类
能源科技引用本文复制引用
刘翰林,杨友运,王凤琴,邓秀芹,刘烨,南珺祥,王津,张洪洁..致密砂岩储集层微观结构特征及成因分析——以鄂尔多斯盆地陇东地区长6段和长8段为例[J].石油勘探与开发,2018,45(2):223-234,12.基金项目
国家科技重大专项“中生界低渗透储层非均质性评价技术”(20162X05050006) （20162X05050006）
国家科技重大专项“中生界延长组低渗透储层微观评价技术”(2011ZX05044) （2011ZX05044）
国家自然科学基金“鄂尔多斯盆地延长组连续型岩性油藏成藏机理与地质特征”(41102083) （41102083）
西安石油大学研究生创新基金(YCS17111014) （YCS17111014）
