Patent ID: 6418380
Filing Date: 2002-07-09
Classification: G01V

Abstract:
A seismic processing method to solve an eikonal equation to determine a travel time (t) of a sound wave between a seismic source at a first set of coordinates (xs,ys,zs) and a point underground at a second set of coordinates (x,y,z), comprising:a. extrapolating on a velocity variable along a vertical axis in a direction towards the point underground from a second point along a vertical axis in a direction away from the point underground by integrating through finite differences vz as a function of vx and vy using the formula (d2v2)&it;(vx2+vy2+vz2)-(2v)&it;(xvx+yvy+zvz)+1-(v2c2)=0â€ƒwherein i. d is a distance between the point underground and the second point; ii. v is a ratio of d to a propagation time; iii. c is a speed of the propagation; iv. x, y, and z designate spatial Cartesian coordinate axes, z being the vertical axis; and v. vx, vy, and vz are spatial derivatives of v with respect to their respective axes; and b. determining the travel time (t) as a function of step (a).