A New Wave of Illumination -ISS OBC Acquisition in the Columbus Basin

2014 ◽  
Author(s):  
T.. Rampersad ◽  
A.. Cegna ◽  
C Steiner ◽  
J.. Kommedal

Abstract The Independent Simultaneous Source (ISS) seismic acquisition in the southern Columbus Basin conducted by WesternGeco for BPTT is in the early stages of seismic processing. Early results are already revealing improved imaging and structural interpretations. Improvements in imaging and depth conversion are compelling, largely the result of full azimuths, longer azimuths, higher fold, lower frequency content and P/Z recording. Because of these factors the resultant OBC data leads to improved velocity model building utilizing BP's Full Waveform Inversion, FWI, techniques. In a field wide comparison done in the southern part of the basin the OBC image provided marked increases in the following over the heritage streamer data; Fault clarity, where reflector terminations and linkages are much clearer.Reflector continuity, especially in the deeper (greater than 12,000 ft. depths). This improvement seen throughout the dataset is most noticeable below shallow gas accumulations and in areas next to platforms previously only covered by lower fold data. Seismic sequences are also now more interpretable.Flat-spot detection where previous identification was unknown.Early results also point to improved spatial positioning of reflectors under shallow gas accumulations and, in the depth migrated volumes, the removal of the sag due to incorrect velocity fields. This paper illustrates comparisons in the Columbus Basin between the new OBC data and heritage streamer data in support of the above claims of improved image and depth positioning.

2020 ◽  
Author(s):  
C. Pérez Solano ◽  
G. Chang ◽  
R. Plessix ◽  
K. Bao ◽  
A. Stopin ◽  
...  

First Break ◽  
2016 ◽  
Vol 34 (10) ◽  
Author(s):  
A.R. Ghazali ◽  
R.J.J. Hardy ◽  
T. Konuk ◽  
R.I. Masiman ◽  
K. Xin ◽  
...  

2013 ◽  
Author(s):  
Fatiha Gamar-Sadat ◽  
Olivier Michot ◽  
Robert Soubaras ◽  
Geoffroy Pignot ◽  
Amir Kabbej

2019 ◽  
Vol 7 (2) ◽  
pp. SB43-SB52 ◽  
Author(s):  
Adriano Gomes ◽  
Joe Peterson ◽  
Serife Bitlis ◽  
Chengliang Fan ◽  
Robert Buehring

Inverting for salt geometry using full-waveform inversion (FWI) is a challenging task, mostly due to the lack of extremely low-frequency signal in the seismic data, the limited penetration depth of diving waves using typical acquisition offsets, and the difficulty in correctly modeling the amplitude (and kinematics) of reflection events associated with the salt boundary. However, recent advances in reflection FWI (RFWI) have allowed it to use deep reflection data, beyond the diving-wave limit, by extracting the tomographic term of the FWI reflection update, the so-called rabbit ears. Though lacking the resolution to fully resolve salt geometry, we can use RFWI updates as a guide for refinements in the salt interpretation, adding a partially data-driven element to salt velocity model building. In addition, we can use RFWI to update sediment velocities in complex regions surrounding salt, where ray-based approaches typically struggle. In reality, separating the effects of sediment velocity errors from salt geometry errors is not straightforward in many locations. Therefore, iterations of RFWI plus salt scenario tests may be necessary. Although it is still not the fully automatic method that has been envisioned for FWI, this combined approach can bring significant improvement to the subsalt image, as we examine on field data examples from the Gulf of Mexico.


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