从储层构型到“地震构型相”——一种河流相高精度概念模型的表征方法

摘要

碎屑岩油气储层构型是指不同级次储层构成单元的形态、规模、方向及其叠置关系.由Miall(1985)运用于河流相储层表征.碎屑岩油气储层构型是储层非均质性的直观表现,直接影响到油气藏开发效果,如何进行精细构型表征是关系到能否正确量化开发指标、或者能否正确描述剩余油分布进而有效减少低效井比例的关键因素.针对渤海明化镇组河流相沉积储层厚度低于地震分辨率的先天不足,对各种构型在地震数据约束下可分辨尺度上进行分类,形成3种构型7类样式的分类体系:垂叠型、侧叠型和孤立型3种砂体构型,垂叠型、密接触侧叠型、疏散接触侧叠型、离散接触侧叠型、下切侵蚀河道孤立型、决口扇孤立型、孤立河道7类样式.研究了每类构型的地震响应特征,阐述了地震属性描述图版,概括了“地震构型相”将构型类型与地震响应有机结合,构建了基于地震构型相的高精度概念模型表征方法.鉴于目前地质建模和数模技术前提下无法对各类储层构型很好地网格化,建立“等效意义”的概念模型开启了一种很好的技术途径.%Clastic reservoir architecture,which was applied to fluvial facies reservoir characterization by Miall in 1985,refers to geometric shape,scale,orientation and superposed relationship of reservoir units of different orders.Clastic reservoir architecture is an intuitive quantitative measure of reservoir heterogeneity characterization,influencing the effect of reservoir development directly.Thus,how to undertake fine architecture characterization is the key to whether reasonable quantitative development indexes or proper description of remaining oil distribution can be described so as to effectively reduce the ratio of low-efficiency wells.With an aim of overcoming the natural restriction that the thickness of fluvial facies deposition reservoirs of the Minghuazhen Formaion in Bohai bay is less than minimum requirement of seismic resolution,this study carried out the classification for the various reservoir architectures constrained by seismic data in a distinguishable scale for seismic data.A classification of three architectures and seven types has been established.Based on seismic response characteristics of each architecture and description of relevant seismic attributes,"seismic architecture facies",which combines architecture types with their seismic responses,constitutes a characterization method of "seismic architecture facies" based high-resolution conceptual model.Our study shows that although various reservoir architectures cannot be well gridding on the basis of present geological and numerical modeling technologies,the equivalent conceptual model may be an applicable technological approach.