Advanced 3D Land Internal Mutiple Modeling and Subtraction, a WAZ Oman Case Study

Retailleau, M.; Benjamin, N.; Pica, A.; Bendjaballah, M.; Plasterie, P.; Leroy, Sylvie; Hugonnet, P.; Khalil, A.; Gülünay, Necati; Smith, Richard S.; Shorter, J.

doi:10.3997/2214-4609.20148809

Cited by 2 publications

(3 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These stronger reflectors referred to as multiple generators (Weiglein et al, 2011), are identified as significant sources of interbed short period multiples. Secondly, velocity estimations within the shadow zone did not properly account for this lower than normal velocities during data processing and this is likely responsible for the curtain of noise observed in the shadow zone (Retailleau et al, 2012). Aikulola et al (2010) related chaotic and distortive reflections observed beyond 3 s at the footwall of regional faults in the delta exhibits lower than normal seismic velocities, and associated these to the onset of overpressure regimes.…”

Section: Discussionmentioning

confidence: 99%

“…They are known to have short periods, low velocities and amplitudes than the desired primary reflection signals. Because of these characteristics, they are not readily distinguishable from primaries, since they have almost the same arrival time and exhibit a dispersed character that creates a curtain of noise often stronger than the primary events (Retailleau et al, 2012). The study area is located in an onshore field in southeastern Niger Delta (Figure 1).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Multiples in Onshore Niger Delta from 3D prestack seismic data

Azuoko¹,

Ehirim²,

Ebeniro³

et al. 2017

Int. J. Phys. Sci.

View full text Add to dashboard Cite

The presence of multiples has been investigated in Onshore Niger Delta using 3D seismic data. The aim of the study was to investigate the characteristics of reflection events beyond 3s two way time on seismic data behind the boundary faults associated with the shadow zone. This involves detailed velocity analysis on semblance plot panel and accounting for moveouts due to reflections away and within the shadow zone. Interval velocity-depth models were generated from the velocity analysis and analyzed for shadow effect in the data. Results of the study revealed the presence of two velocity scenarios Onshore Niger delta. These are the primary and lower than normal velocities away and within the shadow zone, respectively. The interval velocity-depth models and their overlays on the seismic show a constant increase of velocity with depth for the primary model wh ich seems normal, but this is contrary to the lower than normal velocity model where low seismic velocities predominate beyond 3s two way time (3.8 km), especially at the footwall of the boundary fault. These variations are likely due to the fact that sediments at the footwall of the boundary fault are thicker, compacted and thus yield stronger reflectors than the corresponding sediments away from the faults. The lower than normal velocity reflections in the absence of overpressure and anisotropy, which are also causes of low velocity reflections, are attributed to interbed multiple reflections in the data.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Multiples in Onshore Niger Delta from 3D prestack seismic data

Azuoko¹,

Ehirim²,

Ebeniro³

et al. 2017

Int. J. Phys. Sci.

View full text Add to dashboard Cite

show abstract

“…The input gathers for the modeling are subject to strong de-noising and coherency enhancement after application of high frequency surface consistent static corrections. See Retailleau et al (2012) for more details. In the second step, the numerous internal multiple models are simultaneously subtracted from the raw data.…”

Section: Methodsmentioning

confidence: 99%

Two Strategies for Attenuating Internal Multiples in Land Data

Retailleau¹,

Shorter²,

Farran³

et al. 2014

All Days

Self Cite

View full text Add to dashboard Cite

Two new internal multiple attenuation methodologies are presented. The first approach uses a 3D wave equation based multiple modeling technique followed by 3D adaptive subtraction. The recorded data are back propagated/propagated through a reflectivity model (obtained from a preliminary migration) of the overburden. All possible multiple raypaths are modeled by using different combinations of two sub-windows in this reflectivity model. Each combination results in a specific multiple model. The generated multiple models are then simultaneously adapted and subtracted from the input data. The second approach is a 3D dip extraction and filtering technique, taking advantage of any dip discrimination between the primaries and multiples. It works on post stack and pre stack volumes. We show how the two methods are complementary and how they can be combined.The first approach can be applied to any seismic data plagued with strong internal multiples and is perfectly adapted to modern dense, wide azimuth surveys. The second approach works on any seismic volume in which multiples and primaries have different dips in a given domain.Some real data examples from South Oman 3D seismic datasets are shown. All are characterized by a heavy multiple contamination, generated by strong shallow reflectivity sequences in a flattish overburden, and overlying deeper, weaker and heavily structured primaries. By revealing structures previously invisible, these techniques add a lot of value to existing seismic data sets.The generation mechanism of internal multiples is often quite complex making them difficult to predict. The main benefits of the methods described here are that they work in absence of move out discrimination and without the need of a precise identification of the internal multiple generators.

show abstract

Advanced 3D Land Internal Mutiple Modeling and Subtraction, a WAZ Oman Case Study

Cited by 2 publications

References 7 publications

Multiples in Onshore Niger Delta from 3D prestack seismic data

Multiples in Onshore Niger Delta from 3D prestack seismic data

Two Strategies for Attenuating Internal Multiples in Land Data

Contact Info

Product

Resources

About