Patent ID: 7046581

Claim:
A method of obtaining a spatial model of a property of part of a subsurface formation located between underground spaced-apart seismic receivers, said method comprising the steps of: (a) positioning in a borehole a first set of seismic receivers and positioning in a borehole a second set of seismic receivers; (b) selecting at least one pair of seismic receivers, wherein each pair of seismic receivers consists of a seismic receiver i of the first set and a seismic receiver j of the second set; (c) recording for the pair(s) of seismic receivers i and j signals s i (t) and s j (t) obtained from a seismic source; (d) obtaining for each of the pair(s) a transmission response r ij (t) of the formation between the two seismic receivers of the pair by solving (s i (−t){circle around (x)}s j (t))=r ij (t){circle around (x)}(s i (−t){circle around (x)}s i (t)), wherein the symbol {circle around (x)} denotes convolution and wherein s i (−t) is the time-reverse of the signal s i (t); (e) selecting a path-related attribute of the transmission response r ij (t) that corresponds to the property of the subsurface formation; and (f) applying a tomographic reconstruction technique to the path-related attribute of the transmission response(s) r ij (t) to obtain the spatial model of the property of part of the subsurface formation.