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 ...
Technical Content
Quantifying the effects of TTI in multiphysics analysis of electromagnetic data offshore Malaysia
Quantifying the effects of TTI in multiphysics analysis of electromagnetic data offshore Malaysia
Marine sediments are often electrically anisotropic at a scale that affects controlled source electromagnetic (CSEM) data. When the sedimentary sequence is steeply dipping, it is important to model the data using resistivity fields that follow the sedimentary bedding, which is called tilted transverse isotropy ...
Leveraging TLFWI and FWI Imaging to overcome geological complexities and acquisition challenges in onshore Mexico
Leveraging TLFWI and FWI Imaging to overcome geological complexities and acquisition challenges in onshore Mexico
In onshore southern Mexico, thick Mesozoic intervals, extensive salt, and over-pressured shale pose significant challenges for seismic imaging. Leveraging newly acquired data with longer offsets, higher fold, and improved low-frequency signal, we adopt a time-lag full-waveform inversion (TLFWI) driven workflow to resolve the complex ...
Tackling subsalt complexity with elastic FWI using long-offset, low-frequency sparse OBN data
Tackling subsalt complexity with elastic FWI using long-offset, low-frequency sparse OBN data
In recent years, full-waveform inversion (FWI) techniques have evolved significantly - from acoustic FWI (AFWI) that works surprisingly well in salt environments to the latest elastic FWI (EFWI) and high-frequency EFWI Imaging that provides unprecedented clarity in subsalt imaging - largely driven by rapid ...
Deblending of long-offset, low-frequency sparse OBN data under multiple types of interference
Deblending of long-offset, low-frequency sparse OBN data under multiple types of interference
Simultaneous source acquisition significantly enhances ocean bottom node (OBN) survey efficiency, but it also introduces blending noise contamination in continuous recordings. Deblending, which separates primary source signals from blended data, is a crucial step in preprocessing for both 3D and 4D imaging using conventional ...
Imaging the Delaware Fill Zone with ultra high-density data and high-frequency land FWI
Imaging the Delaware Fill Zone with ultra high-density data and high-frequency land FWI
An advanced imaging flow including 40 Hz full-waveform inversion (FWI), in conjunction with an industry-supported ultra-high-density survey provides a high-resolution FWI velocity model and FWI Image to resolve complexities related to the Cenozoic sedimentary fill in the Delaware Basin. The more accurate of the ...
High-definition OBN seismic processing to enhance the interpretability of sand intrusions in the Balder-Ringhorne area of the North Sea
High-definition OBN seismic processing to enhance the interpretability of sand intrusions in the Balder-Ringhorne area of the North Sea
The main reservoirs in the Balder and Ringhorne areas consist of large Paleocene sand mounds as well as Eocene sands, including thin and steeply dipping injectite bodies. Imaging of the targets in the legacy towed-streamer data is challenging due to sub-optimal signal-to-noise ratio, kinematic ...
Revealing Complex Subsalt Mesozoic onshore using Time-Lag FWI and FWI Imaging in onshore Mexico
Revealing Complex Subsalt Mesozoic onshore using Time-Lag FWI and FWI Imaging in onshore Mexico
The Sureste Basin in southeastern Mexico contains complex geological features, including extensional and compressional structures, salt deformations, rafted Mesozoic sections, and over-pressured shale diapirs. A recent onshore seismic acquisition using dynamite sources yielded lower-frequency, longer offset, full-azimuth data than previous vintages. However, permitting challenges ...
Three Images from One North Sea Dark Fibre - PP, PS, and Multiple Imaging
Three Images from One North Sea Dark Fibre - PP, PS, and Multiple Imaging
Distributed Acoustic Sensing on seafloor fibre optic cables (Surface DAS) provides a cost-effective alternative to Ocean Bottom Seismic. Measuring the change of a fibres optical response over time yields a record of strain along the cable, which can be converted into a seismic signal ...