摘要
时频分析是地震资料处理和解释中一种强有力的工具,通过对地震波信号进行时频分析,可以获得地震波的吸收衰减梯度属性,从而应用于储层的含油气性检测.将目前时域局部化性质很高的三参数(TP)小波变换和谱拟合方法引入吸收衰减计算中,通过对TP小波时频谱进行子波谱估计获得更平滑、能量聚焦性更好的时频谱,然后利用最小二乘曲线拟合从中提取稳定的地震波低频段和高频段吸收衰减梯度,以期更好地进行储层含气性检测.实际资料的处理分析结果表明,不论是低频吸收衰减梯度,还是高频吸收衰减梯度,对致密砂岩含气储层的预测结果均与实际情况吻合较好,能够清晰可靠地指示含气储层的部位,且与基于瞬时谱分析提取的归一化地层吸收剖面的分析结果一致,有利于刻画含气储层空间展布,直接指示油气存在,为油气检测提供了一种有效可行的手段.
Time-frequency analysis is a kind of powerful tool in seismic data processing and interpretation. Through the timefrequency analysis of seismic signal, the absorption attenuation gradient attributes of seismic wave can be obtained, which are applied in hydrocarbon reservoir detection. In this paper, we introduce three-parameter（ TP） wavelet with very high time domain localization property and wavelet spectrum fitting method to the calculation of absorption attenuation gradient and apply wavelet spectrum fitting to TP wavelet time-frequency spectrum to obtain more smooth spectrum with better energy focusing properties,then extract more stable low-frequency and high-frequency absorption attenuation gradient by using the least-squares curve fitting,in order to get better gas-bearing reservoir detection. Actual data processing and analyzing results show that both low-frequency absorption attenuation gradient and high-frequency absorption attenuation gradient,their prediction results of tight sandstone gas-bearing reservoir are in good agreement with actual situation, and can clearly indicate gas-bearing reservoir in a reliable way to help characterize the spatial distribution of gas-bearing reservoir. In addition,the analysis results of absorption attenuation gradient are consistent with that of normalized formation absorption profile extracted based on TP wavelet instantaneous spectral analysis. This provides an effective and feasible means for hydrocarbon detection in seismic data fine interpretation.
出处
《地球物理学进展》
CSCD
北大核心
2016年第4期1725-1731,共7页
Progress in Geophysics
关键词
三参数小波变换
子波谱拟合
最小二乘法
吸收衰减梯度
含气性检测
three-parameter wavelet transform
wavelet spectrum fitting
least square method
absorption attenuation gradient
gas-bearing detection
