Diffraction Imaging: Towards Clearer Images of Hydrocarbon Reservoirs

 

PhD Candidate: Brydon Lowney

Supervisor: Dr. Ivan Lokmer, Prof. Chris Bean & Dr. Gareth O'Brien

Funded by: Science Foundation Ireland through iCRAG

Abstract:

When evaluating hydrocarbon exploration prospects, it is essential to understand the network of faults and fractures in the subsurface, in order to better quantify potential leakage and compartmentalisation risk and make an informed decision about the optimal well placement. Hence high-resolution seismic imaging is of great importance to de-risking exploration prospects. However, the standard seismic reflection imaging has its limitations, one of which is relatively low resolution, leading to a failure to identify small subsurface features.

A great potential for improving the resolution of subsurface images lies in so-called Diffraction Imaging technique. Coming to an obstacle or irregularity whose size is of the order of the wavelength, seismic waves experience diffraction, the process which creates recognisable hyperbolic patterns on seismic images. These diffraction patterns are used to precisely image very small subsurface features, such as fault edges, pinch-outs, channel edges, or inter-channel features, commonly invisible in standard seismic reflection images. Although the theory of diffraction imaging is well established (e.g., used in nanotechnology), its use for seismic imaging is novel and its benefits and pitfalls are yet to be systematically investigated.

 

References:

Bansal, R., and Imhof, M., 2005. Diffraction enhancement in prestack seismic data: Geophysics, (70), no. 3, 73-79. 

Fomel, S., 2002, Applications of plane-wave destruction filters: Geophysics, (67), no. 6, 1946-1960.

Moser, T.J., and Howard, C., 2008, Diffraction imaging in depth: Geophysical Prospecting, (56), 627-641. 

Popovici, A., Sturzu, I., and Moser, T.J., 2015, High resolution diffraction imaging of small-scale fractures in shale and carbonate reservoirs: Unconventional Resources Technology Conference, Conference Proceedings, 1-9.