Abstract：High-density seismic acquisition means that the group interval is less than the common acquisition group interval (reaching to 10m, even 5m, that is to infill the spatial sampling) and even is acquisition pattern without array at single point, in which the main aim is to increase the resolution of seismic data. However, in recent years, the reports showing good results by using high-density seismic acquisition in the western complex surface areas of China have been reported in many literatures and seminars, which mistaken the results of such technical measures as folds and processing tools in high-density seismic acquisition for the merits of high-density seismic acquisition. Analyzing the influence of earth absorption, array effects and moveout within array on cutoff frequency of recorded high frequency in the representative land areas, the paper considered ①that main influence on the attenuation of useful waves is strong earth absorption, while array relative to group interval is not main factor. The main issue faced with the seismic acquisition in western areas of China is strong lateral scattering interference and severe attenuation of seismic waves by absorption of strata, resulted in poor seismic S/N ratio and weak high-frequency signals when reaching to surface, which are beyond the receiving scope of seismograph or are submerged into secondary interference and environment noises, making the received seismic dominant frequency cannot reach to higher frequency. In such situation, even using high-density seismic acquisition may not help to improve the S/N ratio and is meaningless if without improving the S/N ratio, and only resulted in increasing field acquisition efforts and processing difficulty while without any meaningful results. ② If work area is in offshore area, because the seawater is free from the absorption effect and without elevation difference within an array, reducing the group interval can greatly increase the recorded highest frequency of target, and the high-density seismic acquisition can meet significant effects.
李庆忠, 魏继东. 高密度地震采集中组合效应对高频截止频率的影响[J]. 石油地球物理勘探, 2007, 42(4): 363-369.
Li Qing-zhong, Wei Ji-dong. Influence of array effect on cutoff frequency of high frequency in high-density seismic acquisition. OGP, 2007, 42(4): 363-369.
