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LIVE WEBINAR – Implications of Shallow Subsurface Scattering for Onshore Seismic Acquisition and Processing

Tuesday, 6 April @ 11:00 am - 12:00 pm (Australia/Perth time)

Free – $10

To view the event video and associated handouts (if any), please either log in to your active PESA membership account or enter the event password you received when you registered for this event.

Guest Speaker(s): Christof Stork

Christof Stork graduated with a Ph.D. in geophysics from Caltech in 1988 and then a Postdoc at Stanford.  He has been involved with 5 startup companies, of which 4 1/2 were successful, and has been a leader in reflection tomography, wave equation migration, FWI, and land acquisition considerations.  Christof has twice had a measurable impact of greater than $1 billion on the industry with Wave Equation migration and RTM.  After founding Land Seismic Noise Specialists in 2017, he has been focusing on developing novel ways to reduce the noise present in land data, as well as trying to improve acquisition designs to try to capture that noise more coherently.

Kindly supported by Rock Flow dynamics

 

This live webinar will take place at:

11am              – Perth
12.30pm       – Darwin, Adelaide
1pm                – Brisbane, Canberra, Hobart, Melbourne, Sydney

Use the calendar link on this page to add this event in to your own calendar at the correct local time for your location.

Tickets are free for members (please log in to see this) and $10 for non members.

Please buy your tickets and immediately follow the link in the ticket e-mail (not the calendar invite or this webpage, which is just generic and not event specific) to set up your registration with the webinar software well in advance of the time of the talk. Once registered with the webinar software you will receive a reminder e-mail 1 hour beforehand.

 

Implications of Shallow Subsurface Scattering for Onshore Seismic Acquisition and Processing

Presented by Christof Stork

Abstract

We propose that a major cause of land seismic noise is from micro-scattering in the near surface and this explains many problems we see with land seismic data.  With surface velocities in the 100-200 m/sec range, strong elastic heterogeneities on a scale of 1-10m have a big effect.  In contrast with the more studied macro-scattering noise (scatter size > ~30m), micro-scattering noise is very difficult to record unaliased or to model and subtract.  However, micro-scattering, which especially affects the high frequencies, is a physical phenomenon that is repeatable.  It can be treated as a predictable distortion effect of signal and noise rather than purely producing unwanted energy.  We show that this surface distortion from near surface scattering can be measured from data and corrected.  This suggests there is more signal in our noisy data than we think, it can be recovered, and we should focus more during acquisition to help processing methods resolve the scattering distortion.

This micro-scattering noise is very difficult to remove because it is so strong, travels in all directions, often has short wavelengths, and appears as unorganized, complex noise.  Whereas macro-scatter modelling and removal has some success, micro-scattering is very difficult to model and subtract because of its small scale.  Tight inline spacing can remove the inline component of the noise, which is about 50% of the scattered noise, but this may not be sufficient when the noise is 10-100 times stronger than the signal and we desire to remove >90% of the noise.  Relying on very high fold and aggressive statistical methods to remove the scattering can be expensive because S/N only improves by the square root of fold.

A novel micro-scattering distortion correction approach has several significant implications for acquisition and processing:
1) Tight inline spacing is likely not the optimal use of hardware in areas of strong micro-scattering,
2) New processing methods can recover significant signal rather than just attenuate noise,
3) Collecting more independent, distributed source and receiver locations helps the processing steps to measure and correct micro-scattering distortion, and
4) There is significant potential benefit from avoiding placing sources and receivers in the noisiest micro-scattering locations.

Details

Date:
Tuesday, 6 April
Time:
11:00 am - 12:00 pm
(Australia/Perth time)
Cost:
Free – $10
Event Categories:
  • Venue

    GotoWebinar (ONLINE EVENT SERVICE)
    The internet Australia

    Organizers

    PESA Western Australia
    PESA Webinars

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    $ 10.00 inc GST