Imaging dipping layers in horizontal well borehole seismic surveys

Carlos E. Nieto, Robert R. Stewart

This work analyzes how the location and number of sources affects the imaging quality of dipping layers using borehole seismic techniques in horizontal wells. A MATLAB program was written and used to model and image a geological scenario. A diffraction modelling algorithm was used to obtain the shot gathers.

Assuming a walk-away surface source and two different models, it was found that in order to properly image steeply dipping layers, either long receiver arrays in the horizontal well or greater source offsets would be required. It is also important to have a symmetrical source spread with respect to the receiver array. Additionally it was found that fine source spacing does not improve the quality of the seismic image substantially.