Subsea Karst detection and imaging improvement using Full Waveform inversion

This paper describes the construction of a high-resolution anisotropic FWI model that is used to help image a karstified carbonate layer and also to help define the underlying clastic reservoirs. The karst zones show extreme velocity rugosity, especially as compared to the surrounding sediments. Conventional reflection tomography cannot resolve the anomalous velocities, and the resulting seismic images below these karstified carbonates are distorted and poor for interpretation. This paper presents the strategies for determining the appropriate input data for FWI and how to build a multi-layer horizon-constrained anisotropic model and the uplift that results from using Q-factors .