准噶尔盆地石南油气田头屯河组成藏模式

The Exploration of Toutunhe Lithologic Reservoir in Shinan Field, Junggar Basin

位于准噶尔盆地腹部的石南油气田头屯河组为辫状河沉积,岩性主要为灰褐色岩屑砂岩和褐红色、灰黄色泥岩,砂岩沉积厚度7～26m,属中-低孔隙度、低渗透率储集层。油藏侧向为泥岩遮挡,构造低部位受油水界面控制。研究表明,断裂、不整合对侏罗系上部及白垩系油气运聚具有重要意义,白垩系与侏罗系及侏罗系头屯河组与西山窑组之间的两期不整合面为主要的油气运移通道,局部的正断层起着沟通油源与储集层的作用。

The Toutunhe formation of Shinan field in hinterland of Junggar basin is dominated by braided fluvial deposits with grey-brown lithic sandstone, brown-red and grey-yellow mudstone, and sand depositional thickness of 7～26 m, being a reservoir of medium-low porosity and low permeability. The reservoir is laterally screened by mud and controlled by oil-water interface at low position of the structure. The study shows that the faults and unconformities are dominant in petroleum migration and accumulation of top Jurassic and Cretaceous. The two-stage unconformities between the Cretaceous and Jurassic and between Toutunhe and Xishanyao formations of Jurassic are major channels for petroleum migration, whereas the local normal faults play roles in connecting the oil sources to the reservoirs.