Study On The Method Of Pre-stack P-wave Azimuthal AVO Fracture Detection And Its Dispersion

Fractured reservoirs account for a large proportion of the world's oil and gas reservoirs.Fracture developed in carbonates,tight sandstones,and unconventional shale reservoirs are often important reservoir space for oil and gas.At the same time,the fracture acts as a migration channel for oil and gas and acts as a connecting reservoir space.In the process of exploration and development,the prediction of fracture is very important for the discovery of hydrocarbon reservoirs.Based on anisotropic theory,using the amplitude azimuthal anisotropy of fracture media,the pre-stack P wave data is used to study the linear and nonlinear inversion of azimuth AVO fracture parameters(fracture density and fracture orientation)to describe.the condition of fracture development in the reservoir.Firstly,this paper studies the linear inversion process of fracture parameters,and discusses several factors that may affect the final inversion results during seismic data acquisition,processing and inversion through numerical models and actual seismic data.It is believed that the use of omnidirectional high-density acquisition,anisotropy migration in local angle domain and denoising inversion methods can lay a solid foundation for better inversion results.Then the paper studies the nonlinear inversion of fracture parameters and gives a nonlinear inversion method.The numerical model and the application of actual data prove the effectiveness of the method.It provides a solution for how to make full use of large offset information in conventional fracture inversion.Fracture fluid prediction has always been a research hotspot,and dispersion is regarded as one of the important means of fluid prediction.However,the conventional dispersion formula is based on isotropic theory.But the actual underground medium is a complex anisotropic medium.Thus,the anisotropic dispersion formula is derived based on anisotropy theory and applied to fluid prediction.It has achieved certain effects and provided a new method and new idea for fracture fluid prediction.