Study Of Forward And Inversion Of Wave Equation And The Seismic Response Characteristics Of Buried Hill Reservoirs

The current Chinese oil and gas exploration has gradually entered the subtle oil and gas reservoir exploration stage, because of the buried hill oil and gas reservoir with good exploration prospects, buried hill oil and gas reservoir is a hot, focus and difficult of the subtle oil and gas exploration.Due to the complicated geological processes, the heterogeneity of buried hill reservoir is strong, the buried hill oil and gas reservoir are irregular block distribution, and the seismic response characteristics are complex and variable. In order to guide the prediction of buried hill reservoir better, it is necessary to analyze and summarize the characteristics of seismic response of buried hill reservoir.Forward of wave equation is an effective means to study the rule of the seismic wave propagation. It is the basis of seismic exploration and seismic inversion. Forward of wave equation plays an important role in distinguishing the interpretation pitfalls verifying interpretation scheme and improving the understanding the geological laws. Based on the forward of wave equation, we can classify, identify and summary the seismic response characteristics of buried hill fracture and different lithology and physical properties of reservoir seismic and we can improve the understanding of the complex wave field response characteristic and propagation law of buried hill reservoir layer. It can guide the interpretation and prediction of buried hill reservoir and improve the accuracy of prediction of buried hill reservoir.Wave equation inversion is suitable to inverse the parameters of underground medium with complex structure.It starts from the wave equation simulation and makes full use of the kinematic and dynamic information which is contained in the seismic records. It can inverse the parameters of medium from seismic data, thereby it reduces the seismic signal distortion which is caused by seismic data processing which is required by conventional pre-stack or post-stack inversion of seismic data. Wave equation inversion can provide accurate physical parameters for structure interpretation and reservoir prediction which play an important role in reservoir description, lithological seismic exploration and development seismic research. On the other hand, the inversion of wave equation plays a vital role in improving the imaging precision of buried hill.This paper is based on the research and application of favorable reservoir prediction method in Buried hill seismic exploration of Bohai. This paper summarizes the results of previous studies. First of all, I derivate and program the wave equation forward modeling of acoustic, elastic wave, viscoelastic medium, transverse isotropic medium(TI) and program pre-stack elastic wave reverse time migration, acoustic post-stack reverse time migration and two-dimensional time domain elastic wave equation inversion. On the basis of previous studies, a new formula for calculating the gradient is proposed, and the calculation accuracy and efficiency are improved. The correctness of the method is verified through model calculation and correlation methods are applied to the study of seismic response characteristics of Bohai Sea buried hill reservoir. Combining with the practical data, I summarize the seismic wave field rules and response characteristics of 8 kinds of buried hill models and focus on the influence of crack to buried hill reservoir, which provide theoretical basis for further understanding of the seismic response characteristics of fractured buried hill reservoir and have important theoretical and practical value.