Applied Research Of Vibroseis And Explosive Source In Hong Sipu Area Ningxia

In geophysical seismic exploration,the excitation source of seismic signal is divided into dynamite source and non-explosive source.Vibroseis were first used in petroleum exploration in Xinjiang,however,there are not many examples of vibroseis in coal exploration.All the seismic sources used in Ningxia region were dynamite,however,in the central and western regions of Ningxia,such as the Hong Sipu area,the Zhongwei Xiao Hongshan area and so on,because the shallow seismic geological conditions are extremely complex,which is difficult to form holes.The source of explosive cannot be excited in ideal layer,which is difficult to obtain ideal excitation effect by using explosive source excitation.In this thesis,a large number of experimental data,original data parameters and Stack section are used to compare the dynamite source and vibroseis in Hong Sibao area of Ningxia.The following questions were explored: The main reason why the excitation effect of explosive source is not ideal;The specific parameters of vibroseis excitation include vibration table number,scanning frequency,scanning length and equal selection method of driving electricity;The vibroseis parameters applicable to the central and western regions of Ningxia were determined,Finally,the application prospect of vibroseis excitation is discussed.In this thesis,a large number of single-shot experiments and studies on explosive source excitation and controllable source excitation are carried out in the experiment plot.Exploring the excitation principle of explosive source,it is considered that the thickness of non-phreatic water level and deceleration layer varies greatly,and a large number of broken and Poorly Cemented gravel or pebble layers exist in the superficial layer,because drilling rig drilling is very difficult,The source of explosive is often unable to excite in the ideal horizon.It leads to the development of surface wave,multiple wave and other interference waves in the single shot record of explosive source.The effect of post-processing data is not satisfactory,which is the main reason for the difference of final superimposed profile;Exploration of vibroseis excitation principle and parameter setting principle,selection of parameters referring to the number of excitation stations,shaking table times,scanning frequency,scanning length and driving level of vibroseis.Comparative study through repeated experiments,the excitation parameters of vibroseis suitable for test area are determined.From the results,this parameter not only guarantees the excitation effect,meets the technical requirements,but also ensures the construction efficiency.A comparative study of superimposed profiles of single shot and section tests between vibroseis and explosive sources.It is considered that it is feasible to use vibroseis as excitation source in this type of area,and the excitation effect is better than that of explosive source.Finally,the future development and application direction of vibroseis are discussed.It is considered that the application prospects of large tonnage and low frequency vibroseis in deep seismic exploration and ultra-high frequency vibroseis in urban geological exploration are broad.