Seismic Wave Field Analysis Of Fluid Replacement Based On Heterogeneous Bodies

Heterogeneous medium is the most common geological body in actual production and the development process is often accompanied by fluid replacement.In this paper the seismic response characteristics after fluid replacement in heterogeneous media are studied.In order to solve this problem,two methods of rock physics experiment and numerical simulation of rock physics model are used in this paper.In this paper,a rock model with different heterogeneous strength is designed,which is realized by adding steel beads to the right side of the reservoir.The rock physical models with different saturation and different fluids are collected by 3D data acquisition and conventional 3D processing.Before the data analysis,the time shift data of different fluid states need to be processed by post-stack mutual equalization.The standard layer is selected as the top interface of the cap layer with saturated oil data.By mutual equalization,the integral error of three groups of data(oil,water and gas)is effectively eliminated,and the consistency between the data is improved,and the seismic attributes of the difference profile are obtained in time.The heterogeneity of the medium has a great impact on seismic imaging,and the differential response is very obvious.When the seismic response is homogeneous,the seismic response accords with the theoretical results;when the heterogeneity is strong,the variation of the seismic response is more complex.Then,a full-band two-scale model is established on the basis of simultaneous jet flow model and patch saturation model.The velocity and attenuation of rock physical models with different saturation and fluid(oil,water and gas)are simulated and analyzed.Compared with the single scale model,the velocity and attenuation appear double steps and double peaks respectively.When saturated with water and oil,the velocity and attenuation are similar,the velocity of gas is relatively small,and the attenuation is larger.Based on this,the accuracy of fluid identification can be improved...