Mécanique et mathématiques numériques en sciences géologiques
A hybrid computational method for crosswell seismic inversion
Liao, Wenyuan (1) and Danping Cao (2)
(1) University of Calgary, (2) China University of Petroleum

The waveform tomography, or full waveform inversion (FWI), is in general better than the ray tomography, however a reliable initial model is usually required to ensure the success. In this work we designed a cascade-like hybrid tomography technology to solve the crosswell seismic inversion problem. The new method is a combination of several widely used tomography technologies. We start from the Radon-transform based back projection (BP) method, which produces a smooth initial velocity model. Next, the Linear Iterative Reconstruction (LIR) method such as SIRT is adopted to update this initial model, then it is further improved by the nonlinear Gradient-based Eikonal Equation Tomography (GEET) method. The velocity model reconstructed from the previous multi ray tomography methods is sufficiently reliable to serve as the initial model for the computational intensive waveform tomography, from which the accurate velocity model is obtained. The numerical example shows that this hybrid method has great potential in reconstructing accurate acoustic velocity or other high-resolution reservoir characterization between two wells. It is noticeable that this hybrid method is able to obtain accurate velocity even when the recorded seismic data is in poor coverage at spatial and the signal-to-noise ratio is low.

Mardi, 18 juin, 11h30
Salle Du Jardin