Seismic Techniques
Crosshole Seismic Surveys
Outline
Crosshole seismic surveys involve measurement of the travel time of seismic energy transmitted between two or more boreholes in order to derive information on the elastic properties of the intervening materials. One hole is used to deploy the source whilst the other hole(s) are used to detect the arrival of the seismic energy. The travel times of the seismic waves are derived from the first-arrivals identified on the seismic trace for each shot-receiver position and are used with the known distance(s) between the shot/receiver boreholes to calculate the apparent velocities (P and S) for each depth interval. This data is then used to derive a vertical profile of the various elastic moduli.
