水淹层小波包能量特征识别方法

Wavelet packet energy characteristic identification of water flooded layer

储集层的声波时差和电阻率曲线间微差形态波形的复杂程度隐含着储集层含油气性的信息。油层水淹程度不同,其小波包能量特征差异较大。无论水淹程度如何,小波包能量均随频率增大呈指数递减;水淹程度越重,小波包能量减小趋势越明显。某些频率成分的能量因水淹类型不同表现出极大差异,水淹层和纯水层能量表现为被吸收削弱,而油层和弱水淹层则表现为能量增强。对于利用传统测井解释理论判别比较困难的“低电阻率油层和高电阻率水淹层(水层)”,基于测井信息的小波包能量特征识别方法有较强的识别能力。

The petroliferous information is disclosed by the acoustic time and resistivity logs. The energy characteristic of wavelet packet varies greatly with different swept extent, and the wavelet packet energy is an exponential decline curve along with frequency augmentation without reference to water flooded extent. Along with water flooded extent increasing, the wavelet packet energy is declining in evidence. The energy in some frequency components shows great difference for different water flooded types. The energy of the swept layer and water layer are absorbed, while the energy of oil and weak water flooded are increased. The wavelet packet energy characteristic method based on the log signal could well identify the lowly resistive oil layer, highly resistive swept layer and water layer, which are done poorly by the conventional log explanation theory.