古风化壳的裂缝性碳酸盐岩储层测井分类评价方法研究

A Log Classifation and Evaluation Method for Fractured Carbonate Reservoir in Weathered Zone

鄂尔多斯盆地下古生界风化壳储层是具有高度的非均质性及繁多的储集空间类型。下古生界风化壳气藏测井评价的关键是通过测井方法对储层进行精细分类划分有效储层,对工业性产层与低产、低效层的界定。基于储层分类的概念,根据常规测井响应,采用聚类分析和判别分析理论,将鄂尔多斯盆地靖边地区下古生界风化壳储层划分为裂缝-溶孔型(Ⅰ类)、孔隙型(Ⅱ类)、裂缝-微孔型(Ⅲ类)等3类;论述了各类储层的主要特征,分类方案考虑了测井资料的可分辨性。在此基础上建立基于聚类分析及判别分析的储层分类判识模型,对测井资料进行归一化、标准化处理,提取能有效反映储层特性的表征参数。实际应用效果表明,分类结果与试气结果吻合较好,判识符合率达到80%以上,使常规测井资料得到了更深入、更广泛的应用。

The weathered reservoir of Ordovician system in Eerduosi Basin has higher heterogeneity and many kinds of reservoir spaces. The fine identification and zonation on effective reservoir are the key point of log evaluation in this weathered reservoir of Ordovician system, and also the point how to compartmentalize industrial layer and low-productivity layer. Based on the basic concept of reservoir classification and conventional log responses, the weathered reservoir of Ordovician system of Jingbian Gas Field in Eerduosi Basin is classified with cluster analysis and discretion analysis theory into three classes fractured cavity reservoir （class Ⅰ）, porosity reservoir （class Ⅱ） and fractured microporosity reservoir （classⅢ）. Detailed are every kind of reservoirs main characters; and the reservoir zonation scheme considers the log data resolvability, based on which established is the reservoir classification and identification model. The log data are normalized and standardized to get effective reservoir＇s characteristic parameters. The field cases indicate that the classification result is consistent with the production result, the consistent rate above 80%, therefore, the conventional log data have been widely used in reservoir evaluation.