基于K-均值聚类和贝叶斯判别的冲积扇单井储层构型识别

Recognition of single well reservoir architecture in alluvial fan based on K-means clustering and Bayes discrimination

单井构型划分是储层构型研究的基础,传统的人工单井构型划分效率低、主观性强、划分标准不统一。为此,以沧东凹陷冲积扇为例,以岩心及测井资料为基础,通过岩心描述、K-均值聚类、贝叶斯判别等方法,形成了基于K-均值聚类和贝叶斯判别的冲积扇单井储层构型识别方法。将该方法应用于非取心井,计算构型识别准确率,明确了造成构型识别准确率低的主要原因。研究表明:基于K-均值聚类和贝叶斯判别的冲积扇单井储层构型识别主要包括取心井构型划分、构型划分标准建立、构型判别公式建立及非取心井构型识别四个步骤,通过岩心观察划分准确的单井构型、建立适用于非取心井的构型划分标准和判别公式最为关键;由于测井曲线的分辨率所限及构型单元过渡带的岩性变化等原因,非取心井构型识别准确率与构型单元厚度呈正相关关系,7级、8级、9级构型单元识别准确率依次降低。

The division of single well reservoir architecture is a basic research.The problems are less effective,human factors and different standards to divide reservoir architecture using traditional methods.Taking the alluvial fan in the Cangdong sag as a case,we propose a single well reservoir recognition method for alluvial fan based on core description,K-means clustering and Bayes discrimination with core and well data.Applied for the well not cored,the reservoir architecture in the well was recognized accurately,and the cause why previous recognization was not accurately was found.The new method works in four steps:divide the reservoir architecture in the well cored,build the dividing standard,define the discrimining formula,and identify the reservoir architecture in the well not cored.It is important to define the standard and identification formula for the well not cored based on the reservoir architecture divided in the well cored.Due to low resolution of logging data and lithologic changes in the transition belt,the accuracy of identifying the reservoir architecture in the well not cored positively depends on the thickness of the reservoir architecture unit.Generally,the recognition accuracy of seventh-,eighth-,ninthorder reservoir architecture units reduces in turn.