基于最大熵的岩心水驱波及系数求取方法

A calculating method for waterflooding sweep efficiency of core based on
maximal entropy

王任一

中国地质大学，湖北 武汉 430074 中海油湛江分公司勘探开发部，广东 湛江 524057

China University of Geosciences,Wuhan 430074, China Department of Exploration and Development,
Zhanjiang Company, CNOOC, Zhanjing 524057, China).

对水洗检查井岩心水淹程度的定性分析，是了解水驱油田波及系数大小的最直接手段。提出了一种利用现场水洗检查井密闭岩心劈开面荧光图像资料，直接求取水驱油藏的波及系数的定量方法。主要采用数字图像处理技术，基于最大熵的图像二值化算法，从熵角度充分考虑水淹目标区和未水淹的背景区可分割边界区域信息量最大的特征，求取最优阈值，可较准确对岩心劈开面图像上的水淹区域面积进行估算。此法为直接利用油田大量的检查井的岩心资料，定量求取水驱油藏的波及系数开辟了一条新的思路。

The qualitative analysis of core waterflooding level is the most direct method for understanding sweep efficiency of
waterflooding oilfield. This paper suggests to check the fluorescence image data of sealing core splitting surface by
inspection well in order to obtain the sweep efficiency of waterflooding reservoir. Based on the image binarization algorithm
of maximal entropy, the paper analyzes the maximal information characteristics for the divisible boundary areas of the target
area with waterflood and background area without waterflood from the entropy angles to get optimized threshold value
through using the numerical image processing technique. The flooded area of core splitting surface can be estimated
accurately through the method. This method introduces a new thinking to quantitatively obtain the sweep efficiency of
waterflood reservoir by direct use of considerable core data of checking wells.