Patent ID: 6510105
Filing Date: 2003-01-21
Classification: G01V

Abstract:
A method of obtaining an image of an underground formation around a borehole extending through the underground formation, which method comprises the steps of:(a) arranging an omnidirectional source and a three-component receiver in a first position in the borehole; (b) activating the omnidirectional source to generate seismic energy and recording with the three-component receiver data in the form of the components of the reflected seismic energy with the three-component receiver; (c) determining from the components of the reflected seismic energy the directions from which the reflected seismic energy arrives at the three-component receiver as a function of two-way travel time; (d) selecting a number of underground positions in the formation; (e) selecting a first underground position; (f) calculating the arrival direction of a ray extending from the omnidirectional source to the underground position and back to the three-component receiver and two-way travel time of seismic energy passing along the ray; (g) accepting the data if the calculated arrival direction is substantially equal to an arrival direction as obtained in step (c) pertaining to reflected seismic energy having the same two-way travel time, and mapping the accepted data on the underground position; and (h) selecting a next underground position and repeating steps (f) and (g) until the last underground position to obtain the image of the underground formation comprising a set of data mapped on underground positions.