准噶尔盆地独山子背斜油水特征及油气成藏规律探讨

Hydrocarbon Accumulation in Dushanzi Anticline of Junggar Basin

孔隙流体包含有油气成藏的重要信息。通过对独山子背斜沙湾组原油地球化学特征分析,推测油气主要来源于中下侏罗统湖相泥岩;根据地层水资料,在垂向上,沙湾组上部砂体连通性较下部好,在平面上,砂体展布主要受沉积相带控制。综合分析了独山子背斜油气成藏规律,来自于中下侏罗统的油气通过独山子断裂向上运移至沙湾组,被上部塔西河组泥岩封盖而聚集成藏,油气成藏主要受油源分布和砂体发育程度控制。还分析了开发区内剩余油可能的分布及其剩余油气资源潜力和勘探目标,提出了独山子背斜进一步油气勘探的方向。

Pore fluid is an important tool to study hydrocarbon accumulation. Through the analysis of geochemical properties of crude oil in Shawan Formation of Dushanzi anticline, it is proven that the hydrocarbon came from lacustrine shale. According to the subsurface water, in the vertical, the connectivity of the upper sandstone is better than that of the lower sandstone, and in the horizon, the distribution of sand-stone is controlled by the sedimentary microfacies. The oil in Dushanzi came from Lower-Middle Jurassic, and then reached Shawan Formation through Dushanzi reverse fault. The distribution of source rock and the development degree of reservoir are the main factors to control hydrocarbon accumulation. Lithologic hydrocarbon reservoirs may be found in the lower members of Shawan Formation.