Investigation into the applicability of AVO techniques to coal mine exploration
Abstract
AVO (for Amplitude Versus Offset) is a seismic technology known in the oil
industry for its ability to differentiate gas sands (over oil producing reservoirs) from
wet sands (over non-producing reservoirs) in the Gulf of Mexico. Its applicability to
a broad range of exploration fields has led to its potential application within the
ADEMA (Advances in Exploration Methods and Applications) project being
considered. Within the frame of this project, this PhD thesis assesses the ability of
AVO to detect a difference between Mudstone and Sandstone roofs over a 6 meters
thick coal seam, in the region of Daw Mill (UK). It moreover presents a
modification of a triaxial cell aimed at calibrating AVO in the laboratory, and
thereby improving the quality of AVO analysis in general.
The analysis presented in this PhD thesis leads to the conclusion that in this region,
the particular rock properties can lead to a signal difference detectable by AVO.
However, analysis of seismic data confirmed that tuning effect interferes with these
distinct signals, and prevents AVO technology to differentiate mudstone from
sandstone roofs.
Finally, this thesis proposes different technical recommendations for successfully
running a test with the modified triaxial cell in future.