Single Well Imaging in cased borehole by interferometry

We performed an interferometry experiment to simulate seismic signals in a single well. A seismic vibrator source was used to generate vertical and horizontal components of ground motion along a surface seismic line, and an array of 3C seismic receivers to record the signals in the borehole. The recorded traces are processed to obtain virtual sources in the borehole, and to simulate single well imaging (SWI) gathers with variable offset in the array. We compare results obtained by processing the real data with synthetic signals calculated by numerical simulation, and analyze the signal bandwidth and amplitude versus offset to evaluate near-field effects. The analysis shows that the method provides an approximation of the direct and reflected SWI signals, with results depending on the available coverage for interferometry. Good quality reflections are detectable in the simulated SWI sections.