Year: 2023 First Published: IMAGE Authors: Peter Scholtz*, Truong Nguyen and Arash JafarGandomi Summary Corrections for source and receiver positioning and clock-drift errors are early steps in the processing of ocean bottom seismic (OBS) data. We have implemented an optimization process to correct jointly for these errors, while a water velocity model gets updated from […]

Year: 2023 First Published: IMAGE Authors: Peter Scholtz, Truong Nguyen, and Arash JafarGandomi Summary Correcting for source and receiver positioning and clock-drift errors are early steps in the processing of ocean bottom seismic (OBS) data. We have implemented an optimization process to correct jointly for these errors, while a water velocity model gets updated from […]

Year: 2023 First Published: EAGE Authors: Susanne Rentsch*, Jim Thompson, Robbin Adams, David Moore, and Ronny Raborn Summary OBN survey numbers have been steadily increasing over recent years. However, those surveys come with new challenges compared to streamer or cable acquisitions. One of the main challenges is that most nodes are autonomous and cannot communicate […]

Year: 2023 First Published: EAGE Workshop Authors: Rentsch Summary Recently, towed marine seismic acquisitions are intently focusing on enhancing low frequencies on the source and receiver side. In this workshop we document our journey to enhance the low- frequency output of airgun arrays for towed marine seismic acquisitions. We show the physical effect of (partial) […]

Year: 2023 First Published: EAGE Authors: Chris Purcell and Lorenzo Casasanta Summary The subsurface of the Caspian Sea presents many complexities in the near surface, such as active mud volcanoes and gas chimneys that make velocity model building and seismic imaging challenging. In this work we showcase the impact of modern broadband processing and high-end […]

Year: 2023 First Published: EAGE Workshop Authors: Melbo Summary The first marine vibrators were introduced in the 1960’s. However, compared to airguns these early vibrators were bulky, slow and failure prone. Consequently, airgun technology has dominated the market for more than 50 years. Over the last few years, there has been a renewed interest in […]

Year: 2023 First Published: EAGE Authors: A. Kumar, R. Rastogi, A. Srivastava, B. Mahajan Summary Reverse time migration (RTM) is a widely used method in seismic imaging, particularly in situations where other migration methods may not be effective, such as in complex geologies. However, traditional RTM images are affected by a strong low wavenumber noise, […]

Year: 2023 First Published: EAGE Authors: Mahesh Kalita, Chris Purcell, and Lorenzo Casasanta Summary Full-waveform inversion finds a subsurface model that minimizes the misfit between modelled seismic data and observations. It’s well known that the L2-norm of the waveforms difference is prone to cycle-skipping due to the presence of local minima. We introduce the soft-dynamic […]

Year: 2023 First Published: IMAGE Authors: Mahesh Kalita*, and Lorenzo Casasanta Summary Full-waveform inversion (FWI) aims to obtain accurate subsurface models by minimizing the discrepancy between observed seismic data and modeled data. However, the commonly used L2-norm waveform difference misfit functional is prone to cycle-skipping due to local minima. To address this issue, we propose […]

Year: 2023 First Published: IMAGE Authors: Mahesh Kalita, and Lorenzo Casasanta Summary We introduce soft-dynamic-time-warping-divergence and its sharp variant as misfit functionals in full- waveform inversion (FWI). These functionals maintain convexity for large model perturbations, making FWI less vulnerable to cycle-skipping. The sharp variant aims to remove the entropic regularization term from the warping process. […]