低渗—特低渗白云岩储层成岩相分析及测井识别——以伊陕斜坡马五段为例

为研究低渗—特低渗白云岩储层的成岩相测井识别方法并进行定量划分，明确白云岩成岩相的空间展布及其有利区，依据岩心观察、普通薄片和铸体薄片鉴定、以及阴极发光分析等，结合X射线衍射和物性资料，对伊陕斜坡中东部马五段白云岩储层的成岩环境及成岩作用进行剖析，通过测井曲线的交会分析与软件的综合应用，构建了低渗—特低渗白云岩储层成岩相的定量识别标准。结果表明，低渗—特低渗白云岩储层成岩相可划分为早期大气淡水溶蚀亚相、表生期大气淡水溶蚀亚相、浅埋藏活跃回流渗透云化亚相、浅埋藏隐伏回流渗透云化亚相、钙质胶结相和泥质充填相等6类；以Pe-DEN，R_LLD-DEN交会及R_LLD-AC交会为代表的测井参数交会图法及软件综合应用是进行低渗—特低渗白云岩储层不同成岩相单井纵向上定量识别与连续划分的有效方法；白云岩储层成岩相在空间的分布具有纵向分带、横向分区的典型特征。有利储层主要分布于早期大气淡水溶蚀亚相和浅埋藏活跃回流渗透云化亚相，其次为表生期大气淡水溶蚀亚相，浅埋藏隐伏回流渗透云化亚相储层分布最少。

Analysis and logging identification of diagenetic facies of dolomite reservoir with low and ultra-low permeability:a case study from Ma 5 member in Yishan slope,Ordos Basin

In order to study the logging identification method and quantitative classification of diagenetic facies of dolostone reservoir with low and ultra-low permeability and clarify the spatial distribution characteristics of diagenetic facies and the favorable exploration area of dolostone reservoir". Based on core observation,identification of ordinary and casting thin section,and cathodoluminescence analysis,combined with X-ray diffraction and physical property data,the diagenetic environment and diagenesis of dolomite reservoir with low and ultralow permeability of Ma 5 member in Yishan slope were analyzed. Then the quantitative identification standard for diagenetic facies of dolomite reservoir with low and ultra-low permeability was established through the crossplot analysis of conventional logging curves and application of software program. The results show that the diagenetic facies of the dolomite reservoirs with low and ultra-low permeability can be divided into six types:early atmospheric freshwater dissolution,supergene atmospheric freshwater dissolution,shallow buried active reflux seepage dolomitization,shallow buried latent reflux seepage dolomitization,calcareous cementation and clay minerals filling. The crossplot method of logging parameters represented by Pe and DEN,R_LLD and DEN,and R_LLD and AC,and the comprehensive application of software program are effective approach for vertical quantitative identification and continuous division of different diagenetic facies of dolostone reservoir with low and ultralow permeability in single well. The spatial distribution of diagenetic facies of dolostone reservoir shows a typical characteristic of longitudinal zonation and planar partition. The favorable reservoirs are mainly developed in diagenetic facies of early atmospheric freshwater dissolution and shallow buried active reflux seepage dolomitization,followed by supergene atmospheric freshwater dissolution,and there is less reservoir deve-loped in shallow buried latent reflux seepage dolomitization diagenetic subfacies.