准噶尔盆地沙窝地地区三工河组二段上亚段相序组合类型

Sedimentary Facies Associations of the Upper Sub-member in the Second Segment of Sangonghe Formation in Shawodi Area,Junggar Basin

准噶尔盆地沙窝地地区三工河组二段上亚段(J1S21)为曲流河三角洲前缘沉积,水下分流河道与河口砂坝2类主要储集砂体垂向上相互叠置,构成削截式与完整式水下分流河道、孤立式河口砂坝、河上坝、下残式与完整式坝上河等相序组合类型,分别形成于向上变深、向上变浅、向上变深复变浅及向上变浅复变深基准面旋回中.其中完整式水下分流河道、下残式与完整式坝上河相序组合类型有利于形成岩性油气藏.

The upper sub-member in the second segment of Sangonghe formation （J1S2^1） in Shawodi area, Junggar Basin is recognized as meandering river delta front sedimentary face. Underwater distributary channel and mouth bar are two main reservoir sand bodies, which can be divided into truncated/complete underwater distributary channel, isolated mouth bar,river-dam and residual/complete dam-river according to sedimentary facies associations. Correspondingly, they are shown as upward deepening, upward shallowing, upward deepening then shallowing, and upward deepening then shallowing on base-level cycles. Among them, the complete underwater distributary channel and residual/complete river-dam phase sequence combination type are more contributed to the formation of lithologic reservoir.