时频重排方法在川西坳陷须家河组地震含气性检测中的应用  

Time-Frequency Reassignment in the Study of Gas Reservoir Seismic Detection of Xujiahe Formation in West Sichuan Depression

作　　者：吴小羊[1] 刘天佑[1] 唐建明[2] 徐天吉[2] 

机构地区：[1]中国地质大学地球物理与空间信息学院,武汉430074 [2]中国石油化工股份有限公司西南分公司勘探开发研究院德阳分院,四川德阳618000

出　　处：《地质科技情报》2008年第3期103-106,共4页Geological Science and Technology Information

基　　金：中国石油化工股份有限公司项目“川西坳陷须家河组地震勘探新技术开发应用”(P05003)

摘　　要：针对川西坳陷上三叠统须家河组储层埋深大、密度高导致地震反射信号有效频带窄、高频衰减快、主频很低的现象,研究采用重排平滑伪Wigner-Ville分布(RSPWVD)对地震信号进行频谱分析。首先采用时域和频域核函数平滑的方法,以抑制信号经Wigner-Ville分布函数频谱分析后产生的交叉项,再将能量的平均值按照区域能量的重心分配,重新安排信号在时频平面内的能量分布。对川西坳陷须家河组工区三维地震反射数据过井剖面进行RSPWVD时频分析,并与常规时频分析方法进行对比的结果表明,RSPWVD适用于地震信号的时频分析,并有利于突出时频的局部化特征和储层的微观结构,时频分辨率得到了提高。Deep embedding depth and high density of the Upper Triassic Xujiahe reservoir of west Sichuan Depression lead to narrow effective band, fast attenuation of high-frequency and low main frequency of seismic signals. In this paper, the rearrangement smoothed pseudo-Wigner-Ville distribution （RSPWVD） is used on the seismic signal spectral analysis. First , the smoothed pseudo-Wigner-Ville distribution with core function is applied to smooth signals in time and frequency domain so that its impact of cross-terms is reduced. Then, the average energy in the time-frequency domain is redesigned according to the barycenter of regional energy in order to maintain a good time-frequency energy distribution. Finally, RSPWVD is adopted to process through-well seismic profile of 3D reflection seismic data of Xujiahe Formation of west Sichuan Depression, and compare with normal time-frequency analysis. The results show that RSPWVD has a better energy focus on the time-frequency locality and a good show of micro-structure of the reservolr.

关 键 词：重排 WIGNER-VILLE分布 时频局域性 地震信号 须家河组 川西坳陷 

分 类 号：P631.414[天文地球—地质矿产勘探]