【摘要】 依据薄层反射的调谐原理,每个薄层产生的地震反射在频率域都有一个与之对应的特定频率成分,该频率成分可以指示薄层的时间厚度。PG地区石炭系残留地层厚度较薄,地震资料主频在25~30Hz之间,分辨率低,常规的地震属性分析和地震反演不能满足石炭系黄龙组(C2h)残留地层厚度预测,特别是地层尖灭线刻画的要求。时频分析技术是采用小波变换,将地震数据变换到频率域,根据地震响应的时频变化规律来研究薄层结构和厚度的一种新方法技术,其中振幅谱描绘时间地层厚度变化,相位谱显示地质体的横向不连续性。应用该技术对PG地区C2h残留地层厚度进行预测,预测结果与钻探成果符合度较高,应用效果较好。更多还原

【Abstract】 According to the tuning principle in thin layer reflection,seismic reflection of each thin layer corresponded to a specific frequency component in the frequency domain,the frequency component could be a good indicator of the time thickness of thin layer.Because the thickness of residual strata of Carboniferous in PG Area was thinner and the low resolution seismic data were at 25~30Hz dominant frequency,the conventional techniques such as seismic attribute analysis and seismic inversion were not capable to predict the residual stratum thickness of Huanglong Formation(C2h)and especially the stratigraphic pinchout line.Time-frequency analysis technique was a new method,which transformed the seismic data into frequency domain by using wavelet transform and analyzed the structure and thickness of thin layer according to the variation of seismic response frequency.Amplitude spectrum depicted the changes of time thickness of strata,while phase spectrum indicated the transverse discontinuities of geological body.The time-frequency analysis based on wavelet transform is used to predict the remnant strata thickness of C2 h.The predicted result is well coincident with that of actual drilling operation,better application effect is obtained.更多还原