An exploration‐scale wide azimuth towed streamer case study

Frømyr, Eivind; Wijnen, Peter; Aaron, Peter; Comeaux, Lynn; Borselen, Roald van

doi:10.1190/1.3059098

Cited by 6 publications

(3 citation statements)

References 4 publications

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“…As more wide-azimuth data has been acquired, the initial promise of better imaging and reduced multiple content has not consistently been fulfilled. Geophysicists have been working hard to understand the issues involved and to develop processing best practices that result in the maximum amount of uplift from wide-azimuth data (Fromyr et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

Enhanced prestack depth imaging of wide-azimuth data from the Gulf of Mexico: A case history

Ma¹,

Wang²,

Reta-Tang³

et al. 2011

GEOPHYSICS

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We present a case study of enhanced imaging of wideazimuth data from the Gulf of Mexico utilizing recent technologies; and we discuss the resulting improvements in image quality, especially in subsalt areas, relative to previous results. The input seismic data sets are taken from many large-scale wide-azimuth surveys and conventional narrowazimuth surveys located in the Mississippi Canyon and Atwater Valley areas. In the course of developing the enhanced wide azimuth processing flow, the following three key steps are found to have the most impact on improving subsalt imaging: (1) 3D true azimuth surface-related multiple elimination (SRME) to remove multiple energy, in particular, complex multiples beneath salt; (2) reverse-time migration (RTM) based delayed imaging time (DIT) scans to update the complex subsalt velocity model; and (3) tilted transverse isotropic (TTI) RTM to improve image quality. Our research focuses on the depth imaging aspects of the project, with particular emphasis on the application of the DIT scanning technique. The DIT-scan technique further improves the accuracy of the subsalt velocity model after conventional ray-based subsalt tomography has been performed. We also demonstrate the uplift obtained by acquiring a wide-azimuth data set relative to a standard narrow-azimuth data set, and how orthogonal wide-azimuth is able to enhance the subsalt illumination.

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Section: Introductionmentioning

confidence: 99%

Enhanced prestack depth imaging of wide-azimuth data from the Gulf of Mexico: A case history

Ma¹,

Wang²,

Reta-Tang³

et al. 2011

GEOPHYSICS

View full text Add to dashboard Cite

show abstract

“…As more data has been acquired, the initial promise of better imaging and reduced multiple content has not consistently been fulfilled. Geophysicists have been working hard to understand the issues involved and to develop processing best practices that result in the maximum amount of uplift from wide-azimuth data (Fromyr et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

Enhanced pre‐stack depth imaging of wide‐azimuth data from the Gulf of Mexico: a case history

Ma¹,

Whiteside²,

Wang³

et al. 2010

SEG Technical Program Expanded Abstracts 2010

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We present a case study of enhanced imaging of wideazimuth data from the Gulf of Mexico utilizing recent technologies; and we discuss the resulting improvements in image quality, especially in subsalt areas, relative to prior methodologies. The input seismic data set is taken from the large scale Freedom WAZ survey located in the Mississippi Canyon and Atwater Valley areas. In the course of developing the enhanced wide-azimuth processing flow, the following three key steps are found to have the most impact for improved subsalt imaging. 1) Data regularization to prepare the data for multiple attenuation as well as for the final run of anisotropic reverse time migration; 2) 3D true azimuth SRME to remove multiple energy, in particular, complex multiples beneath salt; 3) reverse time migration based delayed imaging time (DIT) scan to update the complex subsalt velocity model. The DIT scan further improves the accuracy of the subsalt velocity model after the conventional ray-based subsalt tomography. In this paper, we focus on the depth imaging aspects of the project, with particular emphasis on the application of the DIT scanning technique. We also demonstrate the uplift of acquiring a wide-azimuth data set relative to a standard narrowazimuth (NAZ) data set.

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“…As more data has been acquired the initial promise of better imaging and reduced multiple content has not been fulfilled every time. Behind the scenes, geophysicists have been working hard to understand the processing best-practices that will extract the maximum amount of uplift from wide-azimuth data (Fromyr et al, 2008). New ways to visualize and QC the data have been developed.…”

Section: Introductionmentioning

confidence: 99%

Freedom wide‐Azimuth processing and imaging, a case history study of WAZ imaging in Mississippi Canyon, Gulf of Mexico

Baldock

Camp

Cai

et al. 2009

SEG Technical Program Expanded Abstracts 2009

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Wide-azimuth (WAZ) data is the most significant advance to have occurred in seismic acquisition and processing since the introduction of 3D seismic in the early 1980's. Along with the promise of better subsurface images free of multiples came some unique processing challenges, as well as a new layer of complexity added to processes also found in conventional narrow-azimuth (NAZ) sequences. Here we present an overview of three key steps in a wideazimuth processing flow, using a wide-azimuth data set jointly owned by TGS and WesternGeco in Mississippi Canyon: the Freedom WAZ survey. Data regularization is used to prepare the data for multiple attenuation and imaging; 3D multiple attenuation techniques are used to remove multiple energy, in particular complex multiples beneath salt; and a suite of high-end migration algorithms are used to create the final image of the subsurface.

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An exploration‐scale wide azimuth towed streamer case study

Cited by 6 publications

References 4 publications

Enhanced prestack depth imaging of wide-azimuth data from the Gulf of Mexico: A case history

Enhanced prestack depth imaging of wide-azimuth data from the Gulf of Mexico: A case history

Enhanced pre‐stack depth imaging of wide‐azimuth data from the Gulf of Mexico: a case history

Freedom wide‐Azimuth processing and imaging, a case history study of WAZ imaging in Mississippi Canyon, Gulf of Mexico

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