Application Of High Density 3D Seismic Exploration Technology In Coverage Area Of Thick Magmatic Rock

Based on the first high-density 3D seismic exploration project in Shandong Province,the high-density 3D seismic exploration technology under the condition of large thickness of magmatic rock and complex structure was systematically studied by combining theoretical analysis with engineering practice.Based on the study of the characteristics of deep structure and seismic excitation parameters under large thickness of magmatic rock and extremely complex geological conditions,the reasonable excitation method of field earthquake under large thickness of magmatic rock and extremely complex geological conditions was proposed,and the seismic exploration conditions from shallow to deep strata in the study area were analyzed.The influence of different excitation layers and excitation frequency on seismic exploration was analyzed.The selection method of excitation parameters for 3D seismic exploration was given under large thickness of magmatic rock and extremely complex geological conditions.The application of prestack time migration(PSTM)and prestack depth migration(PSDM)high precision imaging technology under large thickness of magmatic rock and extremely complex geological conditions was analyzed in detail.Application of prediction method of coal thickness based on VMD and SVM was studied in detail.According to the characteristics of original data and geological task requirements,the processing work mainly focuses on six key aspects:Joint static correction technology,spoke preserving noise suppression technology,amplitude compensation technology,frequency extension technology and high-precision imaging technology and VMD and SVM methods.According to the characteristics of seismic exploration under large thickness of magmatic rock and extremely complex geological conditions,the above-mentioned techniques were innovated and applied.Through comparative analysis,the key processing techniques and corresponding parameters were obtained under large thickness of magmatic rock and extremely complex geological conditions.For the first time,three geophysical prospecting units in different industries,including oil field,coal field and geology and mineral industry,were introduced to deal with them separately,so as to improve the reliability and accuracy of data processing.The comprehensive comparative interpretation method of data under large thickness of magmatic rock and extremely complex geological conditions was studied.The data interpretation compares the data bodies of multiple post stack time migration,pre stack time migration and prestack depth migration processed by many units.By analyzing the geometry,kinematics,dynamics or statistical characteristics of seismic wave,the layer attributes and body genera which reflect more obvious structure and coal seam were extracted.The property fusion technology was used to fuse the single attribute above,which reduces the multi solution of data interpretation.Under large thickness of magmatic rock and extremely complex geological conditions,the structural distribution law and coal seam occurrence were obtained,The accuracy of the verification of the roadway is high in the later stage.