DBPapers

OBTANING VELOCITY MODEL WITH KINEMATIC WAVEFIELD ATTRIBUTES BY TOMOGRAPHIC INVERSION

AUTHOR/S: M. SOLEIMANI, I. PIRUZ
Sunday 1 August 2010 by Libadmin2007

7th International Scientific Conference - SGEM2007, www.sgem.org, SGEM2007 Conference Proceedings/ ISBN: 954-918181-2, June 11-15, 2007

ABSTRACT

Making macro velocity model is the most important part in any seismic
data processing system. It is a very time consuming and none accurate step
in conventional methods like NMO/DMO/stack. In this article, we drive a
velocity model for a synthetic data with new introduced tomographic inversion
method. This method uses the kinematic wavefield attributes which would
yield from common reflection surface (CRS) stacked data. These attributes
are normal (N) wave and normal incidence point (NIP) wave curvatures. The
tomographic inversion will be performed in three steps, automatic picking, 2D
inversion and modeling. In automatic picking, a large amount of points on the
reflection events will be picked which assumes to be placed on the subsurface
reflectors. The automatic nature of picking will reduce the time of picking and
improve the signal to noise ratio in final section. In the next step, the travel
times for these points will be calculated by ray tracing technique. At the end, in
final step, the travel times and rays will make the desired section of the macro
velocity model. The other advantage that differentiate this method from others,
is that we can easily test if the model is accurate or not and update is as fast as
possible. In a true model, the events on data volume should be offset dependent
which gained here. This section has a high S/N ratio with more accuracy than
the section which derived from conventional methods.

Keywords: Tomographic Inversion, NIP Wave, Automatic Picking, Ray Tracing,
CRS Stacking