致密砂岩储层成岩相测井识别方法研究

The tight sandstone reservoir as a type of widely distributed reservoir with great hydrocarbon potential, has aroused extensive attention. Complex diagenesis leads to its dense lithology, poor physical property, complicated pore structure and strong anisotropy. Under the condition of certain sedimentary facies, diagenesis facies determines the formation and distribution of sweet spot of tight sandstone reservoir. This project is based on the basic issues of uniform classifications and nomenclature of clastic reservoir diagenetic facies and lack of thorough well-logging method of quantitative characterization, etc. Taking typical tight sandstone reservoirs of different basins as examples, based on diagenesis types, intensity and characteristics of diagenesis minerals, the classification, nomenclature and evaluation parameters of diagenesis are discussed. Through testing data including core and thin sections to calibrate logging, well logging response features of different diagenetic facies can be summarised and then, logging recognition standard of diagenetic facies can be established. Combined with well-logging new technology, eg. natural Gamma Ray Spectrometry log , ECS etc. to calibrate the results of recognition of diagenetic facies, in order to extend the study of diagenetic facies from point to line and plane. The "sweet spot" can be predicted by the distribution of diagenetic facies. This project is expected to made innovative achievements in the aspects of diagenetic facies classification and nomenclature of tight sandstone reservoir, quantitative characterization parameters and well logging recognition methods. 3-4 SCI papers are expected to be published. 1 patents and 1 software copyright are planned to apply.

致密砂岩油气以其巨大的资源潜力可观的规模储量日益引起广泛关注。复杂成岩作用造就了其岩性致密、物性差、孔隙结构复杂且非均质性强的特征。在特定的沉积相背景下，成岩相决定了致密砂岩储层"甜点"的形成与分布。课题立足于砂岩储层成岩相分类方案不统一、且缺乏完善的测井定量表征方法等问题。以不同盆地典型致密砂岩储层为例，在其成岩作用类型、强度及成岩矿物组合特征研究的基础上探讨成岩相系统的分类方案及识别评价参数，然后通过岩心薄片等分析化验资料刻度测井，归纳总结不同成岩相在常规测井曲线上的响应特征，建立不同成岩相的测井识别模式与准则，并结合ECS等测井新技术对成岩相识别结果进行标定，由此将成岩相的研究由点向线和面上拓展，并通过成岩相分布规律对储层"甜点"进行预测。课题预计将在致密砂岩储层成岩相分类体系、定量表征参数及其测井识别方法方面取得创新性成果，发表SCI论文3-4篇，申报专利和软件著作权各一项。

致密砂岩储层成岩相测井识别评价方法正处于储层地质学与测井地质学交叉前沿领域。致密砂岩油气储层复杂成岩作用造就了其岩性致密、物性差、孔隙结构复杂且非均质性强的特征。在石油地质基本特征和沉积相背景明确的条件下，成岩相即决定了致密砂岩储层普遍致密背景下物性“甜点”的形成与分布。项目组成员立足于致密砂岩储层成岩相分类体系缺乏、且测井定量表征方法不完善等存在的科学问题，同时结合鄂尔多斯盆地延长组、四川盆地川中地区须家河组等致密砂岩油气勘探存在的问题。通过自然科学基金面上项目近4年的攻关研究，在储层成岩演化与优质储层发育机理以及储层成岩相测井识别评价方法取得了创新性的成果。该项目：1）归纳总结了四川盆地须家河组、鄂尔多斯盆地延长组等致密砂岩储层成岩相的分类体系和识别方法；2）阐明了不同成岩相储层宏观物性和微观孔隙结构特征，恢复了不同成岩相成岩演化序列和孔隙演化史；3）并进一步深入剖析了不同成岩相在不同常规测井曲线组合上（GR、AC、DEN、CNL、RT等）的响应特征；4）将常规测井与元素俘获ECS测井计算岩石矿物组合剖面以及成像测井孔隙度谱的方法相结合，实现单井成岩相测井识别与划分；5）最后综合提出了基于储层经历成岩作用和强度定性判定以及指示性成岩矿物含量精确计算的成岩相测井识别与定量评价方法。该项目在致密储层成岩演化机理分析、成岩相识别与划分、成岩相时空演化规律、不同成岩相的测井评价以及成岩相的单井测井划分提出了一系列创新性的认识，这对于致密砂岩储层的综合评价与有利发育区带预测具有重要意义。