巴楚地区东河塘组致密砂岩储层成岩相研究

根据沉积学和储层地质学原理和研究方法，利用岩石薄片和扫描电镜等测试分析资料，在储层岩石学和成岩作用特征研究的基础上，开展了巴楚地区东河塘组致密砂岩储层成岩相研究。研究认为，东河塘组储层发育6种成岩作用，以压实作用、胶结作用和溶蚀作用为主，成岩阶段为中成岩A-B期。根据视压实率、视胶结率、视溶蚀率及溶蚀量4个参数值和沥青充填情况，将东河塘组储层划分为中等压实中等胶结强溶蚀相（Ⅰ）、中等压实中等胶结中等溶蚀相（Ⅱ）和中等压实中等胶结弱溶蚀相（Ⅲ）等7种成岩相类型，其中Ⅰ-Ⅲ相为有利成岩相。利用测井资料，采用k最邻近分类算法对研究区17口井进行成岩相测井连续自动识别，得出东河塘组上砂岩段储层成岩相以Ⅵ相为主，有利成岩相主要分布在伽2-玉2-巴5井区和群6-BK8-BT4-KT1井区，下砂岩段储层成岩相以Ⅱ相为主，有利成岩相主要分布在伽2-群6-BK8-巴2-康1井区，比上砂岩段更发育。有利成岩相的研究，可为优质储层预测提供地质依据。

Study on diagenetic facies of the Donghetang tight sandstone reservoirs in Bachu area

Sedimentological principles and investigation approaches were combined with thin sections, scanning electron microscope data on the study of tight sandstone reservoir diagenetic facies in Donghetang formation, Bachu area.The result dictates that reservoirs of the formation were shaped by 6 diagenesis effects but only three of which, namely compaction, cementation and dissolution, had played most part.The Formation was determined to be in an A-B stage of middle diagenesis phase.Based on four parameters (apparent compaction rate, apparent cementation rate, apparent dissolution rate, amount of dissolution) and asphalt-filling of the formation, we recognized seven kinds of diagenetic facies in the formation contains, including medium compaction and cementation with strong dissolution facies (Ⅰ), medium compaction and cementation with medium dissolution facies (Ⅱ), medium compaction and cementation with weak dissolution facies (Ⅲ) and etc., among which, type I to Ⅲ are considered facies with exploration potentials.Relevant log data and the k-nearest neighbor classification method were also used to differentiate continuously and automatically the diagenetic facies of layers penetrated by 17 wells in the research area.The result shows that the upper Formation is dominated by type Ⅵ facies, with the most favorable facies occurring in Ga2-Yu2-Ba5 and Qun6-Bakai8-Batan4-Kangtan1 wellblocks, and the lower part is more developed than the upper one and dominated by type Ⅱ facies, with the most favorable facies occurring in Ga2-Qun6-Bakai8-Ba2-Kang1 wellblock.The study may serve as a geological basis for high-quality reservoir prediction.