Workshop 19

Wavefield complexity: use or lose in least-squares inversion, migration, and modelling
FRIDAY, June 12TH|

Convenors

  • Billy Revelo (bp)
  • Eric Verschuur (Delft University of Technology)
  • James McLeman (DUG)
  • Andrew Ratcliffe (Viridien)
  • John Brittan (TGS)

 

Description

All imaging and inversion algorithms leverage the same physics, acoustic/elastic versions of the wave equation, but it seems they cannot consistently utilise the full wavefield at a production scale to improve results. Why is this? Why do multiples often need to be removed for optimal full-waveform inversion (FWI) results? Why does least-squares migration typically only use primary reflections when least-squares velocity model inversion (FWI) can utilise more of the wavefield complexity? In this workshop, we aim to discuss and identify if issues like these are caused by limitations in the input data, the modelling, the underlying theory, or something else…

Sub-Topics that will be covered in the workshop:

  1. Limitations of input data: implications of sampling and acquisition geometry for handling different parts of the wavefield – transmitted arrivals, primary and multiple reflections
  2. Role of multiples in least-squares imaging: balancing the benefits of additional illumination against the risks of leakage and crosstalk.
  3. Strategies for using transmitted waves versus reflections in FWI. In the case of multiple reflections, when do they enhance results, and when should they be suppressed? If they need to be suppressed, what physics have we failed to capture?

Participant Profile

This workshop will attract researchers and practitioners in the field of geophysics to discuss the gaps we currently see between theoretical and practical applications of common seismic imaging algorithms (i.e., migration, least-squares migration, and least-squares velocity model inversion).

Workshop Programme

TimeActivity
09:00Welcome
09:15Opening Address & Workshop Objectives
SESSION 1: Imaging with multiples: Limitations of acquisition and input data
09:30High-frequency imaging with multiples: why acquisition and subsurface effects matter - James McLeman*, Gary Hampson, and Tom Rayment (DUG)
09:50Multiple imaging with DAS data - Kunpeng Liao (Viridien)
10:10Evaluating the role of free‑surface multiples in 4D Imaging and velocity inversion: A North Sea example - Billy Revelo* and Rodney Johnston (bp)
10:30Panel Discussion
10:50Coffee Break
SESSION 2: Role of multiples in least-squares imaging
11:10Can LS imaging add value in an FWI world? - Angus Lomas (bp)
11:30Internal multiples as source of information - Eric Verschuur (Delft University of Technology)
11:50Acquisition and practical workflows for FWI and LS Imaging with multiples - Simon Baldock (TGS)
12:10Panel Discussion
12:30Lunch Break
SESSION 3: Strategies for using transmitted waves versus reflections in FWI
13:30Multi-measurement and multi-wave MP-FWI - Laurance Letki (DUG)
13:50How we can use the multiples more accurately in full- waveform inversion - Denes Vigh, Xin Cheng and Olivia Lewis (SLB)
14:10FWI Image versus conventional imaging technique on a deep water OBN use case - M. Appe 1 , R. Baina 2 , A. Ben- Hadj Hassine 2 , B. Duquet 1 *, D. Sun 1 ( 1 : TotalEnergies and 2 : OPERA)
14:30Optimizing the Use of Multiples in FWI: Illumination Benefits Versus Crosstalk Challenges - Ali Mohamed (1), Achmad Zaky (1), Anna Glushchenko (1), Guillaume Cambois (2) (1: SLB, 2: ADNOC)
14:50Panel discussion
15:10Workshop Wrap-Up