利用Fisher判别法识别复杂岩性

IDENTIFYING COMPLEX LITHOLOGY WITH FISHER DISCRIMINANT

岩性复杂地区是指该地区由多种岩性组成例如灰质砂岩、细砂岩、泥质砂岩、灰质泥岩及泥岩等,这类地层的岩性复杂状况加大了测井解释的难度。针对S油田沙四段岩性复杂特征,在统计5口井测井资料、岩心和薄片分析资料的基础上,以响应特征相似,测井响应上可以识别为原则,通过Fisher判别方法,对该区主要储层岩性进行了分类,进而对岩性复杂地区的岩性识别进行研究分析。以实例解释与岩心资料为依据,采用Fisher判别方法进行岩性识别研究,利用所得判别公式对80个井段预测的岩性与岩心岩性符合率达到88.8%。

A region of complex lithology is an area with multiple lithology such as lime sandstone,packsand,shaly sandstone,gray substance shale and shale,etc.,which increases the difficulty of well logging interpretation.According to the complex lithology characteristics of Sa 4 section of S oilfield,Fisher discrimination method is used to classify the lithology of major reservoirs in the area and then to identify lithology in a complex region based on similarity of logging response with well logging data,core data and thin section analysis of 5 wells.Through application in 80 intervals,it is showed that the coincidence rate of lithologic identification reached 88.8 % with this method.