为了明确高尚堡油田深层沙三2Es₃²亚段沉积微相、成岩储集相特征及各类成岩储集相的成因机制,利用区域地质、测井、砂岩薄片、铸体薄片、扫描电镜、X衍射分析等多种方法对沉积相、成岩作用及其影响因素进行综合研究,并在此基础上进行成岩储集相划分,探讨各类成岩储集相的成因机制。结果表明,该区Es₃²亚段为一套扇三角洲沉积体,主要发育扇三角洲前缘亚相,广泛发育的水下分流河道和河口坝砂体为油气的聚集提供了有利场所。分析低渗透储层成岩作用对储集物性的影响,得出造成本区储层砂岩渗透率较低的主要机制是成岩期强烈的压实作用及各种自生矿物的充填和胶结作用。结合成岩作用和微观孔隙结构研究,将本区成岩储集相划分为稳定组分溶解次生孔隙成岩储集相、中强压实强胶结残余粒间孔成岩储集相、强压实强胶结剩余粒间孔成岩储集相、极强压实强胶结致密成岩储集相4类,阐述了各类成岩储集相的特征。选用流动层带指标、孔隙度、渗透率、粒度中值、泥质含量、排驱压力、孔喉半径均值和变异系数等参数,采用神经网络模式识别方法,对目的层进行了成岩储集相识别,并结合沉积相,实现了成岩储集相的时空展布。

This paper studies the sedimentary facies, the diagenetic reservoir facies and their origin mechanism in the deep zone of Shahejie formation in Gaoshangpu oil field. Based on the regional geology, the well logging, the sandstone slice, the casting slice, the scanning electronic microscope, and the X-ray diffraction methods, the sedimentary facies, the diagenesis and their influencing factors are studied. The diagenetic reservoir facies are classified and the origin mechanism is discussed. It is shown that the fan delta front deposition is developed, and the extensive distributive channels and mouth bars are the favorable oil accumulation locations. The effect on the reservoir property of diagenesis is analyzed, and it is indicated that the origin mechanism of the low permeability in this area is of the strong compaction, the infill and the cementation of autogenetic mineral during diagenesis. Based on the diagenesis study, the diagenetic reservoir facies are divided into four types and their characteristics are analyzed, including the secondary pores diagenetic reservoir facies with solution of unstable ingredients, the residual intergranular pores diagenetic reservoir facies with middle-strong compaction and cementation, the remaining intergranular pores diagenetic reservoir facies with strong compaction and cementation, and the tight diagenetic reservoir facies with extremely strong compaction and cementation. Using eight chosen parameters, that is, the flow zone index, the porosity, the permeability, the median grain size, the mud content, the expel pressure, the median pore throat radius and the variance coefficient, with the genetic artificial neural network method, the study and prediction models are established, and four diagenetic reservoir facies types are identified in the target formation. Combined with the analyses of the sedimentary facies, the time-space distributions of diagenetic reservoir facies are explained. The result may serve as a guide in the development of low permeability oil fields.