Simulation of Spark Source Wavelet Under Multibubble Motion

摘要

Marine spark sources are widely used in high-resolution marine seismic surveys.The characteristic of a wavelet is a critical part in seismic exploration;thus,the formation and numerical simulation of spark source wavelets should be explored.In studies on spark source excitation,the acoustic field generated by the interaction between bubbles constitutes the near-field wavelet of a source.Therefore,this interaction should be revealed by studying complex multibubble motion laws.In this study,actual discharge conditions were combined to derive the multibubble equation of motion.Energy conservation,ideal gas equation,and environmental factors in the discharge of spark source wavelets were studied,and the simulation method of an ocean spark source wavelet was established.The accuracy of the simulation calculation method was verified through a comparison of indoor-measured signals using three electrodes and the spark source wavelet obtained in the field.Results revealed that the accuracy of the model is related to the number of electrodes.The fewer the number of electrodes used,the lower will be the model's accuracy.This finding is attributed to the statistical hypothesis factor introduced to eliminate the coupling term of the interaction of the multibubble motion equation.This study presents a method for analyzing the wavelet characteristics of an indoor-simulated spark source wavelet.