从沉积学角度研究了陕甘宁盆地陇东地区三叠系延长统长6―长8碎屑岩储层的沉积成因类型及物性特征。查明了:多数组分的孔隙类型主要以粒间孔隙和粒间溶孔为主,少数组分内为孔隙和裂缝孔隙。储层主要有坝顶席状砂、河口坝、水下分流河道、浊积水道和滑塌体微裂缝等5种沉积微相成因类型。对该5种成因储层的物性对比分析表明,该区坝顶席状砂的物性相对最好,河口坝次之,其它3种较差。探讨了沉积因素对储层物性的控制作用,认为在相同的物源区背景下,由沉积环境决定的储层物质组成、构成和结构特征直接影响着储层的优劣。

The article study the genetic classification of sedimentation and physical behavior analysis of the Chang 6-8 reservoir of Triassic Yanchang formation in Longdong area, Shanganning basin by sedimentological method. Intergranular pores and residual intergranular pores are the most important and effect pores, it also include a little of fracture pores. The reservoir stratum include sheet sand over mouth bar, underwater distributary channel,debouch bar,and slip sandstone. It is consider that the sheet sand over mouth bar is the first-rate reservoir, the second is debouch bar, and the rest is not good reservoir. Approach the subject of sedimentation control physical behavior of reservoir from different angles, and consider of that the reservoir of physical compose, constitute and structural features is controlled by sedimentation environment. The reservoir of physical compose,constitute and structural features will control the quality of the reservoir.