The Application Of Full Waveform Inversion In Time-lapse Seismic

The issue of energy has always been an important issue in the development of the world today.With the continuous advancement of technology,emerging energy sources are emerging.However,traditional energy,represen ted by coal,oil and natural gas,still has an irreplaceable position.With the fluctuation of international oil prices in recent years,major oil companies have gradually reduced their exploration investment in new blocks,which makes it more important to tap the potential of old oil fields.The background of the application of this paper-time-lapse earthquake is proposed at the end of the last century,an important technology that can improve oil recovery.This paper briefly reviews the seismic exploration methods,introduces the development trend of full-waveform inversion technology,the concept of time-lapse earthquakes and recent developments,and explains the construction principle of seismic exploration forward modeling and seismic exploration base d on time-lapse.Among them,the seismic exploration forward model is based on the stress-strain relationship,and the frequency domain acoustic wave equation is established.After the selection of the Perfectly Matched Layer absorption boundary condition,the frequency domain acoustic wave forward model is given.The point difference format is discretized,and finally the forward media model is performed on the uniform medium model in the frequency domain.The seismic exploration inversion model considers the characteristics of time-lapse earthquakes,and combines the double-difference full-waveform inversion to attribute the waveform changes to the characteristics of time-varying changes in elastic properties,redefining the target functional,and then pro poses a double The differential inversion model implements the basic inversion algorithm.The seismic exploration inversion model has good applicability in practical applications.Inspired by the basic inversion algorithm,this paper designs a time-lapse seismic inversion algorithm based on the double differential basic inversion algorithm.Firstly,the finite difference contrast source algorithm is used to simulate the seismic parameters before time migration,and then an iterative method for solving the model parameter difference is reconstructed based on the regular-Gauss-Newton method.In the numerical simulation section,numerical simulations were performed for the two time-lapse models.The results show that the algorithm designed in this paper can better describe the time-shift parameter changes,which has certain validity and feasibility.