三相融合沉积微相分析方法

传统沉积微相研究尺度通常为三级层序，不适合储层级别的研究。 三相融合（古地貌、地震属性和砂地比）沉积微相分析方法可以刻画薄互层储层的分布情况。 首先，在单井高频层序划分的基础上，利用分频技术获得高频分频剖面；然后，在高频分频剖面上利用井-震结合追踪高频层序界面，建立高频层序格架，并在古地貌控制下对地震属性进行优选和分析；最后，结合井点砂地比图编制沉积微相图。 沉积微相边界由优选的地震属性指示的边界控制，微相内部结构变化依据砂地比等值线勾画。 运用该方法得到的沉积微相图同时具备了外形和内部结构，比传统的沉积相模式图更精准，在指示有利储层可能发育部位的同时，还可进一步指示“甜点”区的位置。 这种半定量的沉积微相分析方法，提高了有利储层预测的精度。

Analysis method of sedimentary microfacies by combining three facies

Traditional sedimentary microfacies of third-order sequence is too large to guide the reservoir prediction. A method of combining ancient landform, seismic attributes and sand percentage was proposed to analyze sedimentary microfacies and describe the advantageous thin reservoir distribution. The high-frequency sequence boundary can be interpreted on frequency division section by referring to the high-frequency sequence division on single well. Seismic facies of high-frequency sequence was chosen under the control of ancient landform graph. By analyzing the sandstone percentage figure, the sedimentary mierofacies figure was obtained. In this figure, the sedimentary microfacies boundary is controlled by boundary of seismic attributes, and the interior of the sedimentary microfacies is described by contour of sandstone percentage. Comparing with traditional sedimentary facies ideograph, this figure is more quantitative for having the external form and internal structure. It can be used to analyze the possible location of advantageous reservoir and indicate the dessert area. It makes reservoir prediction more real and believable.