瞬时子波吸收分析技术的应用——以中国近海天然气检测为例

Application of instantaneous wavelet absorption analysis technology:case study on offshore gas detection in China

（1.中海石油（中国）有限公司北京研究中心，北京100027；2.中国科学院地质与地球物理研究所，北京 100029）

CNOOC Research Center,Beijing 100027,China

基于地震波在通过含气地层时高频成分衰减剧烈这一性质，通过分析高频成分的频谱可以对储层含气性进行检测。常规吸收分析技术是在地震道上分时窗直接进行频谱分析，分析结果受反射系数的影响较大，难以区分强振幅异常是由地层含气引起还是由高阻岩性引起。基于地震资料相对保幅处理的瞬时子波吸收分析技术，能在复赛谱中实现地震子波和反射系数的分离，排除了反射系数的影响,使分析精度得到很大提高。将该技术应用于中国近海多个海域的天然气检测，其结果与钻探结果相吻合。依据分析结果，进行了有利勘探区预测。

Based on the characteristic that high frequency component of seismic wave was seriously attenuated when going through gas-bearing formation,we can detect the gas-bearing property of reservoir by analyzing the frequency spectrum of high-frequency component.Frequency spectrum analysis is carried out directly in divided time window on seismic traces in conventional absorption analysis technique,but the analysis results are seriously influenced by reflection coefficient,strong amplitude anomaly is difficult to be distinguished whether caused by the gas-bearing or high-impedance of formation.Based on instantaneous wavelet absorption analysis technique for relative amplitude preservation on seismic data,the seismic wavelet and reflection coefficient can be separated in cepstrum,which excludes the impact of reflection coefficient and greatly improves the analysis accuracy.The technique was applied to several offshore exploration areas in China,the result of gas detection coincided with drilling data.The potential exploration area was predicted in terms of the analysis results.