Least-Squares Migration in the Image Domain with Sparsity Constraints: An Approach for Super-Resolution in Depth Imaging

Analysis of Salt Stratification Modeling Influences over Reverse Time Migration Considering and not Considering Least-Squares Schemes

“…The curves in figure 3 give us the quantitative confirmation of the analysis performed in figure 2: the application of least-squares schemes leads to a visible broadening of the data bandwidth, even for the tomography-derived velocity model (orange versus purple lines). It is in total accordance with the analytical demonstration described by Pereira- Dias et al (2017). The more-accurate velocity significantly improves the seismic bandwidth, achieving results very close to the modeled data (gray), and reinforces the interpretation that velocity of intrasalt stratification in least-squares schemes yields better results.…”

“…Despite playing an important role in seismic imaging of subsalt reservoirs, the inclusion of salt stratification is not enough to solve all the imaging issues, because of the unbalanced amplitude below complex salt bodies which may not correctly represent the elastic contrasts in subsurface. Therefore, least-squares schemes seem to be as a cutting-edge tool helping to compensate any poorly illuminated seismic amplitude (Schuster, 1993;Nemeth et al, 1999), and remarkably improving the seismic quality below the salt section, especially in the Santos Basin such as demonstrated in Pereira- Dias et al (2017); Pereira- Dias et al (2018); Shadrina et al (2020). Hu et al (2016) also presented enhancement in the resolution when considering least-squares schemes associated with the Gaussian Bean Migration (LSGBM), which confirms the improvements in resolution when adopting least-squares schemes with migration algorithms.…”

Geological Characterization of Evaporitic Sections and Its Impacts on Seismic Images: Santos Basin, Offshore Brazil

“…Inside the PSDM's border-limit, a myriad of methods is available, ranging from Kirchhoff PSDM to Reverse-Time Migration (RTM). Completing the toolbox of state-of-the-art processing techniques are also Full-Waveform Inversion (FWI) (Ben-Hadj-Ali et al 2008;Barnes & Charara (2009); Operto et al, 2013;Vigh et al, 2014) and Least-Squares Migration (LSM) as per discussed in (Nemeth et al, 1999;Hu et al, 2001;Dias et al, 2017;Wang et al, 2017;Dias et al, 2018).…”

Combination of the Salt Stratifications and the Least-Square Migration to evaluate their Improvements for the Pre-Salt Reservoir Images in the Santos Basin, Brazilian Offshore

“…Adapted from Fonseca et al (2018). Dias et al (2017) emphasized that the use of LSM algorithm could compensate the seismic signal distortions to ensure reliable amplitude responses for seismic images under the salt bodies (Figure 3). Moreover, it enhance the resolution for better definition of thin layers.…”