尚店油田东部沙四中亚段沉积微相研究

综合利用岩心、测井、粒度分析、电镜分析等资料,对尚店油田东部沙河街组的沙四中亚段沉积微相进行了系统研究。结果表明,沙四中亚段为滨浅湖沉积,主要发育坝中、坝缘、泥坪及生物滩4个微相。沙四中亚段沉积早期湖平面相对稳定,之后周期性升降,总的趋势是湖平面相对下降;沉积物主要来自北部及西北方向上的三角洲或冲积扇的水下部分。根据小层划分结果,建立了垂向相模式,绘制出了沙四中亚段的各主力小层的沉积微相平面展布特征图,建立了平面相模式,并总结出了沉积微相平面划相依据,为储层特征研究、油田开发方案的调整和动态分析提供了可靠的地质依据。

Sedimentary microfacies study of middle section of the fourth member of Shahejie formation in east part of Shangdian Oilfield

The sedimentary microfacies of middle section of the fourth member of Shahejie formation in east part of Shangdian oilfield were studied using core,log,particle-size analysis and scanning electron microscope(SEM) analysis.This district belongs to shore-lake and shallow-lake sub-facies of lacustrine deposit,and it is further divided into four microfacies: middle bar,bar edge,mudflat and organic bank.The movement of lake level was relative steady in early deposition.After that it was seasonal and the total trend was descent.Sediments are mainly from underwater of deltas or alluvial fans in the north and in the northwest.On the basis of member division,facies models were built for vertical and plane orientation.The sedimentary microfacies distribution characteristic and division of every main member in middle part of the fourth sands were analyzed.The results can provide a geological foundation for the research of reservoir characteristics and the adjustment and dynamic analysis of oil-gas field development plan.