基于小波熵水淹层识别方法探索

The identification method of the water flooded layer based on the wavelet entropy

储层的孔隙度和电阻率曲线间微差形态波形的复杂程度隐含着储层含油气性的信息,油层水淹程度不同,其时频平面上小波系数能量团存在着显著差异,随水淹程度加重,其能量团分布由复杂逐渐趋于简单单调.油层水淹信息映射在其小波系数能量熵特征上,可使油层水淹信息得到放大,更易于水淹程度识别.基于测井信息的小波熵识别水淹层的方法,对利用传统测井解释理论判别比较困难的低阻油层有较强的识别能力.

The information of petroliferous reservoir is hided in the level of differential waveform complexity between the resistivity and porosity log curves of reservoirs. The wavelet coefficient energy group of time-frequency surface has distinct difference for different swept extent. Along with water flooded extent increase, the energy group distribution gradually tends to be simple. The signal of water flooded reservoir reflects in the energy entropy of wavelet coefficient, which enlarges the information of water flooded reservoir and makes identifying the swept layer easy. The conventional log explanation theory badly identifies the low resistivity oil layer, which is well identified by the identification method of swept layer based on the wavelet entropy of log signal.