Structural distortions are frequently encountered in Abu Dhabi area with significant velocity heterogeneity and complex geological features. Due to the unique challenges, FWI often struggled to accurately resolve small-scale distortions. The hard seabed and ultra shallow water environments lead to significant noise that destabilize ...
Technical Content
Improving the Sub-Volcanic Image through Least-Squares PSDM with TLFWI
Improving the Sub-Volcanic Image through Least-Squares PSDM with TLFWI
Imaging deep targets underneath highly heterogeneous overburden using data from non-ideal acquisition is always challenging. In Block SC38, offshore Philippines, the seismic energy propagation is disrupted by a complex volcanic system in the overburden, leading to washed-out imaging beneath the volcano. The absence of ...
Maximizing the value of the first time-lapse OBN data at Liza field with co-processing
Maximizing the value of the first time-lapse OBN data at Liza field with co-processing
In this case study, we present results from the first ocean bottom node (OBN) based 4D imaging at the Liza field, offshore Guyana. With two nominally repeated OBN surveys acquired within less than a year, we initially employed a parallel 3D processing flow to ...
Geomechanical Risk Assessment for CO₂ Storage in the North Sea’s Luna Site: A Seismic-Driven Coupled Compositional Flow and Geomechanics Approach
Geomechanical Risk Assessment for CO₂ Storage in the North Sea’s Luna Site: A Seismic-Driven Coupled Compositional Flow and Geomechanics Approach
A comprehensive assessment of geomechanical risks is essential for the success of geological carbon storage. Although the relationship between injection-induced pore pressure changes and rock failure is broadly understood in poromechanics, the challenge of characterizing and managing geomechanical hazards associated with subsurface CO₂ injection ...
Monitoring presalt reservoirs with hybrid acquisitions and 4D FWI
Monitoring presalt reservoirs with hybrid acquisitions and 4D FWI
Many fields in the Brazilian pre-salt have been historically imaged with narrow-azimuth towed-streamer (NATS) data and only recently have been surveyed with ocean bottom nodes (OBN). Some cases of time-lapse 4D seismic monitoring are limited to hybrid pairs of data, where a NATS baseline ...
New insights on the role of low-velocity shales in subsalt Paleogene exploration in the deepwater Gulf of Mexico
New insights on the role of low-velocity shales in subsalt Paleogene exploration in the deepwater Gulf of Mexico
New long-offset, low-frequency (LOLF) OBN acquired using the innovative TPS low-frequency source provides transformational imaging of the subsalt geology in the complex and inboard, minibasin domain of the central Gulf of Mexico (GOM). The role of low-velocity (LV) shale bodies in the deformation, which ...
Acquisition and early imaging of a long-offset, low-frequency sparse node survey in the Gulf of Mexico
Acquisition and early imaging of a long-offset, low-frequency sparse node survey in the Gulf of Mexico
Inspired by the successes of sparse ocean bottom nodes (OBN) programs in recent years, especially the industry's first long-offset, low-frequency (LOLF) sparse OBN survey using the Tuned Pulse Source (TPS) as the seismic source (Merritt et al., 2024), Viridien acquired Laconia OBN, its vast ...
Unlocking extra value from vintage WAZ data using EFWI and ERTM: a subsalt imaging case study in the GOA
Unlocking extra value from vintage WAZ data using EFWI and ERTM: a subsalt imaging case study in the GOA
Elastic full-waveform inversion (EFWI) and high-frequency EFWI Imaging have gained increasing popularity, primarily with ocean bottom node (OBN) data, in areas where strong velocity contrasts and associated elastic effects are present, such as the Gulf of America (GOA). However, when only vintage streamer data ...
Time-lapse (4D) seismic monitoring generally benefits from a dedicated co-processing where important inconsistencies between vintages are attenuated. We propose a joint formulation for least-squares migration (LSM) that further mitigates effects such as low repeatability and diverse data quality, by constraining the least-squares inversion with ...