Title: High-resolution seismic imaging down to the reservoir
Supervisors: Joanna Morgan and Michael Warner (2 projects)
The objective of these projects is to apply newly-developed 3D full wavefield tomographic
codes to improve the imaging of petroleum reservoirs beneath complex geological
overburden.
Full-wavefield inversion (FWI) involves finding a velocity model that is able to match the full
seismic wavefield wiggle-for-wiggle. The method involves iteratively updating an initial
starting model using a linearized local inversion. The principal advantage of FWI is the
recovered velocity models have a high spatial resolution. In the figure below, the starting
model (left) has been obtained using conventional industry methods, and the FWI velocity
model (centre) has been obtained by inverting the low-frequency (4-7 Hz) refracted
wavefield. The faults and offsets in the FWI velocity model correlate well with the migrated
seismic data (right).
A number of issues need to be addressed for this technology to achieve its full potential.
These include making the inversion faster and more robust – currently the method is
computationally expensive and requires significant user experience. Other issues include
the requirement to obtain a good starting model and having low frequencies in the field data.
Most significantly, the technique would greatly benefit from the inclusion of the backscattered (reflected) wavefield and higher frequencies in the inversion. The student will
address one or more of these issues, and/or apply these codes to field datasets.
We are looking for geophysicists, physicists, computer scientists, applied mathematicians,
engineers and others with a numerical background and an interest in imaging the Earth in
collaboration with the petroleum industry. Applications from those will experience in scientific
and high-performance computing are particularly welcome. The projects are fully funded by
the petroleum industry for UK and EU students, and can involve close collaboration with the
industry and opportunities for internships around the world.
Morgan et al. 2013, Next generation seismic experiments: Wide-angle, multi-azimuthal, 3D
full-waveform inversion, Geophys. J. Int, doi: 10.1093/gji/ggt345.
Warner et al., 2013. Anisotropic 3D full-waveform inversion. Geophysics, 78,
10.1190/GEO2012-0338.