Patent ID: 8665667
Filing Date: 2014-03-04
Classification: G01V

Abstract:
1. A method comprising: (a) providing a first velocity model derived from a vertical seismic profiling (VSP) survey in an upper region of a subterranean formation defined by the upper region and a target area below the upper region, the upper region containing a wellbore in which a receiver array is placed to obtain vertical seismic profile data (VSP data) representative of the upper region; (b) progressively migrating wave fields representative of the VSP data to a datum line defining a boundary between the upper region and the target area using first virtual sources located at a plurality of geophone positions on the receiver array, to thereby obtain wavefields simulating VSP wavefield data obtained at the datum line; (c) developing interferometric common shot gather data simulating VSP data obtained by the first virtual sources, first hypothetical sources located at the datum line, and hypothetical receivers located at the datum line; (d) developing interferometric common midpoint (CMP) data simulating surface seismic data obtained at the datum line by the first hypothetical sources and second hypothetical sources located on the datum line between the first hypothetical sources and the wellbore, and hypothetical receivers located at the datum line; (e) modifying the first velocity model using the migrated wavefields and the interferometric CMP data, to obtain a second velocity model representative of velocities of the subterranean formation within the target area; (f) saving the second velocity model to a computer readable medium; (g) displaying the second velocity model to a user for interpretation and analysis on a computer display where the second velocity model is rendered as an image; (h) wherein if the second velocity model is deemed satisfactory to the user, establishing said second velocity model as a final velocity model and terminating any further processing; (i) wherein the second velocity model is not yet satisfactory to the user, replacing the first velocity model with the second velocity model; and (j) repeating 1(a) through 1(i) until the second velocity model is deemed satisfactory to the user or the user determines that there is no further improvement in the resulting imaged based upon the latest transformation and said second velocity model is determined to be a final velocity model.