Gradient projection methods with applications to simultaneous source seismic data processing

• Author / Creator

  Cheng, Jinkun

• Simultaneous source acquisition, or blended acquisition, has become an important strategy to reduce the cost of seismic surveys by allowing overlapping between different sources. The major technical challenge associated with this acquisition design is the strong interferences caused by the closely fired shots. This thesis focuses on the separation or the deblending of simultaneous source data via constrained inversion methods. The cost function is the misfit between the predicted and the observed blended data. The constraint is that the desired signal is coherent in the common receiver, common offset, and common midpoint domains when the fire time delay corresponding to each shot is corrected. The simultaneous source interferences would appear incoherent when the randomized source fire scheme is applied. In this thesis, I assume that the desired coherent signal can be represented via a low-rank matrix. The randomly distributed interferences would increase the rank. The coherence constraint for deblending can be implemented effectively by a low-rank constraint in the corresponding data domain. I adopt the gradient projection method that iteratively solves this low-rank constrained inverse problem for deblending. The projection filters are the f-x-y eigenimage filter (Chapter 3) and the Singular Spectrum Analysis filter (Chapter 4) that suppress the source cross-talk artifacts while preserving the unblended signal. Fast implementations of the two reduced-rank filters are achieved via randomized rank-reduction methods. The gradient projection framework is then extended to the direct imaging of simultaneous data via shot-profile least-squares migration.

• Subjects / Keywords

  • Gradient projection
  • Seismic data reconstruction
  • Random projection
  • Least-squares migration
  • Matrix rank reduction
  • Simultaneous source

• Graduation date

  Fall 2017

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R3416TC8F

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.