Abstract:This paper systematically expounds seismic secondary noises generated by alI kinds of surface obstacles and points out that such noises are most noteworthy in seismic prospecting, The complexity of surface secondary noises Iies in the following fiveaspects:(1)The secondary noises may occur on the whole record and they can be neither avoided nor removed.(2)The frequency band of the surface secondary noises 15 nearly the same as that of effective reflection,50 they can not be eliminated by frequency filtering.(3)Low-velocity secondary noise often behaves as random noise.The random noise 15 generally suppressed by statistical method,whose supp-ressing ability,however,15 limited.(4)The secondary noises reach seismic spread from all directions,therefore their aPParent velo-cities on a record are often very high,the highest aPProaching infinity as a limit.The high-velo-city secondary noise from the side 15 50 similar to the effective reflection that they can hardly be distinguished from each other,some highvelocity secondary noises can even be enhanced by stacking;(5)Because the aPParent velocity of high velocity secondary noise 15 generally higher than that of refraction first arrival,the high velocity secondary noise often can not be distinguished from effective reflection in aPParent velocity domain and aPParent wavelength domain.The high velocity secondary noise can not be all eliminated by field geoPhone array method,It can only be treated in data Processing.The one sidedness of noise investigation methods stated in traditional text books of seismology 15 Pointed out in this PaPer.Generally,the high velocity secondary noise can hardly,be found on noise investigation records,on the contrary,it can be found clear on Production records and horizontal stacking sections.Areal geoPhone array 15 the most effective method for suPPressing high velocity secondary noise.This PaPer also shows clearly that linear array has incorrigible defect,makes a concrete account of all kinds of areal geoPhone array and emphasizes that rose analysis should be used to direct the aPPlication of geoPhone array. This PaPer refers to the common demerits in current seismic data Processing.It 15 suggested that the effort for suppressing noise in data Processing should not be Placed only on a single seismic trace.Furthermore,it 15 Pointed out that mixing,2-D filtering and coherence enhancementetc.are the effective methods for elitninating secondary noises.However,the technique for full eliminating secondary noises 15 being exPected.A method for Processing lows ratio seismic data 15 Presented in this PaPer.
引用本文:
李庆忠. 论地震次生干扰——兼论困难地区地震记录的改进方向[J]. 石油地球物理勘探, 1983, 18(3): 207-225.
Li Qingzhong. On seismic secondary noises. OGP, 1983, 18(3): 207-225.