Anisotropic First-arrival Slope and Traveltime Tomography (FASTT)
B. Tavakoli F., S. Operto, A. Ribodetti, J. Virieux and S. Sambolian
Event name: 80th EAGE Conference and Exhibition 2018
Session: Velocity Model Building - Tomography
Publication date: 11 June 2018
Info: Extended abstract, PDF ( 748.5Kb )
Price: € 20
A new formulation for first arrival traveltime tomography is introduced based on the traveltime and slopes of first arrival local coherent events for 2D TTI media. Here, we use Eikonal solvers in forward modeling to calculate slope and traveltime of events, while taking advantage of adjoint state method to design a matrix-free framework for the inversion. We show that slope information makes the inversion more sensitive to the geometry of subsurface structures and significantly increase the resolution of tomographic model compared to traveltime-only inversion. We demonstrate the added sensitivity by slopes information through two examples. We evaluate our approach by estimating the subsurface vertical velocity model for a realistic 2D VTI model (Overthrust). This approach can be a reliable tool for macro velocity model building from ultra-long offset data recorded by coarse node arrays. Among our perspective is combining this tool with reflection slope tomography.