A fast algorithm for 3D azimuthally anisotropic velocity scan |

Finally we consider a field-data example. A subset of the McElroy dataset from West Texas was formed in a supergather (Figure 7). This dataset was studied by Burnett and Fomel (2009), in which they proposed a velocity-independent moveout correction to avoid costly velocity scan. With the fast algorithm, we are now able to compute the semblance efficiently: only 45 s for a single Radon transform when , , and ; direct computation at this sampling would take approximately 30 hours.

Although the original data have been isotropically NMO corrected, the time slice still shows a subtle directional trend to flatness (Figure 7). From the semblance plot (Figure 8), we observe some nonzero values of anisotropic parameters.

super
An isotropically NMO-corrected supergather from the McElroy dataset, West Texas.
,
.
s,
m.
Figure 7. |
---|

semb
Semblance plot computed by the fast algorithm.
,
.
Figure 8. |
---|

A fast algorithm for 3D azimuthally anisotropic velocity scan |

2015-03-27