Alexander Zarkhidze

Extracting regional exploration attributes and insights over the Brazilian Equatorial Margin using multi-input machine learning 2D to 3D ultrasparse reconstruction

Frederico Xavier de Melo, Raúl Ysaccis, Cen Li, Tao Zhao et autres

We developed a multi-input deep learning (DL) algorithm designed to handle ultrasparse 2D vintage projection to 3D cases. The proposed method relies on structural and deterministic information extracted from the 2D seismic and is used to train and execute a multidirectional learning …

Ultralow frequency-enhanced source for OBN survey design and implementation

Franck Le Diagon, Bamba Esinov, Alexander Zarkhidze, Tristan Allen et autres

This paper presents an ocean-bottom nodes (OBN) acquisition planning, testing, and implementation strategy, which uses a hybrid source design in the Gulf of America (GoA). This strategy includes a triple conventional gun array source, and an independent single ultralow-frequency source. The survey …

Generalised Survey Optimisation with Constraints

Rajiv Kumar, Massimiliano Vassallo, Alexander Zarkhidze, Franck Le Diagon et autres

The ultra-long offset ocean-bottom node (OBN) acquisition technique to stabilise full-waveform inversion has already been used successfully in the deep-water US Gulf of Mexico (GoM) characterised by shallow salt bodies hindering accurate earth model building, which is critical for the imaging of …

Inversion-based multistage seismic data processing with physics-driven priors

Rajiv Kumar, Y.I. Kamil, Phillip Bilsby, Anu Narayan et autres

Abstract Various aspects of survey design have a profound impact on how noise appears on the coherent signal of interest, thus impacting conventional inversion methods in complex environments. We propose a multistage physics-driven prior-based processing technique that is versatile and can be …

Multistage matching pursuit Fourier interpolation with physics-based priors

Phillip Bilsby, Rajiv Kumar, Massimiliano Vassallo, Alexander Zarkhidze

Summary The reduction of spatial sampling, as a strategy to reduce the cost of seismic acqusition, requires solutions within signal processing to support and minimise the impact of these geometries on the final data quality. We present an overview of a physics-based …

Spectral Gap-Based Regular or Irregular Seismic Survey Design with Random Time Dithers

R. R. Kumar, Massimiliano Vassallo, Alexander Zarkhidze, Franck Le Diagon et autres

Summary We propose generating an optimal irregular survey design with time or space dithers using the spectral-gap-based rank-minimization technique. The work is first of its kind where a computationally efficient practical seismic survey with random time dithers can be designed using spectral …

Full Waveform Inversion for the Near Surface Characterization, Onshore UAE, Case Study

Rahul P. Dixit, Pavel Vasilyev, Ivica Mihaljević, Michelle Tham et autres

Abstract Full-waveform inversion (FWI) has become a well-established method for obtaining a detailed earth model suitable for improved imaging, near-surface characterization and pore-pressure prediction. FWI for onshore data has always been challenging and has seen limited application (Vigh et al, 2018). It …

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What to Do When Up-Down Deconvolution Breaks Down

D. Boiero, Claudio Bagaini, S. Banerjee, Robert Bloor et autres

Summary The interferometric approach, often referred to as up-down deconvolution, is well-known and applied to attenuate free-surface-related multiples in seabed surveys. In a horizontally layered medium, the upgoing wavefield can be expressed as the convolution of the downgoing wavefield with the earth’s …

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Automated Data-Driven Initial Velocity Model Building for Refraction Tomography

Simone Re, Alexander Zarkhidze

Summary Near-surface characterization is an important part of the land seismic data processing workflow. Conventional approaches rely on refracted waves and estimate the compressional velocity models from the tomography of the first-break traveltimes. Seismic tomography, while extremely powerful for resolving subsurface velocity …

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5D Compressive Sensing Conditioning with Dual Coil Shooting Data

Will Sanger, Alexander Zarkhidze, Massimiliano Vassallo, P. Vascik

Summary We present a new workflow applied to a dual-vessel marine seismic streamer acquisition using a circular-shooting geometry to extract and improve valuable information for the imaging process. In this work, we focus on the results for subsalt imaging. This approach allows …

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A Large-Scale Gulf of Mexico OBC Simultaneous-Source Case Study: Survey Design for Efficient Shot Separation

Alexander Zarkhidze, Luis Arechiga Salinas, Franck Le Diagon, Jeff Thompson et autres

Summary Acquiring seismic data with simultaneous sources, already an established technique for land data, is gaining acceptance for towed-streamer marine data, and is fast becoming the norm for ocean-bottom data. Simultaneous-source acquisition is especially attractive because it can potentially improve both acquisition …

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A large-scale Gulf of Mexico OBC simultaneous source case study: Shot separation

Ian D. Moore, Marcela Ortin, Alexander Zarkhidze, Vazquez C. Alfredo et autres

Simultaneous-source acquisition achieves significant gains in acquisition efficiency by allowing the energy from multiple shots or sources to interfere such that multiple vessels can be acquiring simultaneously and continuously, reducing the overall acquisition time. This interference must then be addressed when processing …

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