One of the main problems with imaging in heterogeneous media is the fact that the rays are generally curved. Imaging methods based on generalised Radon transform that takes into account the curved rays are being developed.
Passive monitoring of reservoirs is a developing technique for managing oil recovery. The frequency and location of micro-seismic events can be used to infer the movement of fluid in the formation. The further use of these events to improve the imaging of the reservoir is being studied. The events are being modelled numerically and from their arrival times their paths through the model will be inferred and the velocity fields reconstructed. This system will invert for travel times using accurate but fast methods of calculation of travel times which are based, not on full waveform finite difference codes, but on other algorithms which are as accurate.
Dr. Andrej Bona (A.Bona@curtin.edu.au),