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. […]

Year: 2023 First Published: IMAGE Authors: Arash JafarGandomi, Aparajita Nath, Sergio Grion Summary Marine seismic vibrators are considered serious contenders to air-gun arrays and are attractive as environmentally friendly sources. While the reduced environmental impact is highly attractive, an additional driver is the ability to control the characteristics of the released energy precisely. Here we […]

Year: 2023 First Published: IMAGE Authors: Jing Sun, Arash Jafargandomi, Julian Holden Summary In multicomponent ocean bottom seismic (OBS) acquisition, hydrophones and geophones (or accelerometers) are employed to record seismic signals. Combining records from the hydrophone (P-component) and the vertical geophone (Z-component) allows for elimination of the receiver-side ghost and water-layer multiples, when performing wavefield […]

Year: 2023 First Published: EAGE Vienna Workshop Authors: Hager, Rentsch Summary Air-gun sources and their environmental impact have been debated for a long time. While some of this debate might be exaggerated it is generally accepted that the high frequencies outside the seismic bandwidth are of no benefit to imaging or subsequent attribute inversions although […]

Year: 2023 First Published: IMAGE Authors: Rodrigo Felicio Fuck and Lorenzo Casasanta Summary We introduce a novel, computationally efficient model preconditioner, the guided filter, a multi-dimensional, structure-oriented, and edge-preserving filter, with a self- adjoint implementation which does not require a priori knowledge of the structural dip field. We show how to generalize the guided filter […]