薄差层水淹级别划分方法

大庆油田由于其特殊的地质因素影响,进入高含水期以后,储层平面、层间、层内非均质性严重,剩余油在空间上分布状况较为复杂,薄差储层发育.在调整开发阶段,开采对象从主力厚油层转向薄差层.常规测井解释薄差层水淹级别误差较大.因此,建立一种针对大庆油田薄差层水淹级别识别技术:首先,计算测井曲线的分形维数,然后通过研究区内关键井研究,选取对薄差层水淹特征敏感的测井曲线及其分形维数作为判别分量,建立标准样本集,最后利用Fisher判别方法实现薄差层水淹级别的自动划分.将该方法应用于大庆油田两口井实际资料处理,并将处理结果与岩心分析结果对比,其符合率达到73.5％.该方法对油田开发中后期薄差层水淹解释是有效的,其精度达到油田现场要求,有助于对薄差层井下状况准确勘测和研究,提高薄差层产量.

Interpretation Method of Thin-Poor Water Flooded Reservoir

Influenced by its special geologic factors,reservoir heterogeneity is severe on plane,at intrabed and in layer and space distribution of the remaining oil is complex after entering high water cut period in Daqing oilfield.At the stage of regulation development,the object of the production changed from major thick oil reservoirs to the developed thin-poor reservoirs.Conventional well logging interpretation on the thin-poor water flooded reservoir has large error.So an interpretation method of thin-poor water flooded reservoirs of Daqing oilfield is proposed.Firstly,the fractal dimension of logging curves is calculated.Then,after the research of key wells in study area,the logging curves and its fractal dimension sensitive to water flooded reservoir are chosen and taking as the discriminant vector to establish the standard sample set.Lastly,automatic interpretation of the thin-poor water flooded reservoir will be realized by Fisher discriminant analysis technique.The coincidence rate of the interpretation and core analysis results reaches 73.5% after the method is applied to actual data treatment for two wells in Daqing oilfield.Therefore,the method is effective to the thin-poor water flooded reservoir interpretation at mid-late development stage with accuracy demands of the oilfield.It can improve the interpretation accuracy and make oil production of the thin-poor reservoirs increase.