Workshop 8

Reflectivity: Why do we still need it when inverting for velocity? Monday, June 8th|

Convenors

  • Robert Soubaras (Aker BP)
  • James McLeman (DUG)
  • Eric Verschuur  (Delft University)
  • Nizar Chemingui (TGS)

Description

A decade ago, when using one-way wavefield propagation methods such as Joint Migration Inversion (JMI), both velocity and reflectivity were jointly inverted. In contrast, with two-way propagation methods like full-waveform inversion (FWI), only velocity was inverted. However, as FWI has advanced to higher frequencies, several approaches have emerged that introduce reflectivity into the two-way formulation, enabling joint inversion of both parameters. This workshop aims to compare one-way and two-way approaches to address key questions: What is reflectivity? Why do we need it? How do we compute it? How do we use it? What is the future of reflectivity?

We encourage submissions containing theoretical and algorithmic considerations, synthetic and real data examples (preferably from the North Sea), and any material addressing the aforementioned key questions.

Sub-Topics that will be covered in the workshop:

  • Joint velocity and reflectivity inversion using one-way modeling
  • Joint velocity and reflectivity inversion using two-way modeling
  • Velocity inversion with two-way modeling with subsequent reflectivity computation
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Participant Profile

Geophysicists and imaging/inversion specialists (research and applied) working on velocity model building, FWI, or reflectivity inversion-based workflows.

Workshop Programme

TimeActivity
09:00Introduction to the workshop - Robert Soubaras (Aker BP)
Session 1: Simultaneous velocity and reflectivity inversion using one-way wave equation
09:30Decoupling velocity and reflectivity, is it useful? - Eric Verschuur (Delft University of Technology)
09:50Simultaneous waveform inversion and low-frequency data - Biondo Biondi (Stanford University)
10:10Integrating EigenRay Direct Arrivals and Azimuthally Varying Angle-Domain Scattering to Recover Reliable Anisotropic Velocity and Reflectivity/Diffractivity Images - Zvi Koren (Aspen Technology)
10:30Questions and discussion
10:50Coffee break
Session 2: Simultaneous velocity and reflectivity inversion using two-way wave equation
11:20Estimating Subsurface Properties from Angle-Dependent Reflectivity with Angle-Domain Multiparameter FWI - Nizar Chemingui*, Raafat Abdul Alim, David Cavalin, Chaoshun Hu, and Khaled Abdelaziz (TGS)
11:40Efficient seismic subsurface reconstruction by combining macro-velocity models and quantitative migrated images - Herve Chauris* and Marc Benziane (STIM, Mines Paris, PSL Research University)
12:00Multiparameter Velocity and Impedance Full Waveform Inversion Using the Spectral Element Method - Ramzi Djebbi, Lorenzo Casasanta* and Hugh Lund (Shearwater GeoServices) Christian Boehm, Lion Krischer, and Michael Afanasiev (Mondaic AG)
12:20 Questions and discussion
12:40 Lunch Break
Session 3: Velocity inversion with reflectivity derived as a post-processing
13:40On the current role and future of reflectivity for understanding elastic attributes with FWI - James McLeman*, Kristian Torres, and Gian Matharu (DUG)
14:00Aspects of multi-parameter full-waveform inversion for amplitude-versus-angle reflection characterisation - Andrew Ratcliffe* and Gordon Poole (Viridien)
14:20Strategies for elastic reservoir characterisation with multiparameter FWI in a sub-chalk North Sea setting - Olivia Lewis*, Andrea Murineddu, Maria Shardrina, Jian mao (Slb), Joachim Mispel, Sonja Maultzsch (Equinor), Christian Hidalgo, Jon Andre Haugen, Ole Edvard Aaker and Håvard Buran (Aker BP)
14:40Questions and discussion
15:00General discussion and closing remarks