Seismic inversion is the process of transforming seismic reflection data into a quantitative rock
property description of a defined reservoir.
Seismic data can be inspected and interpreted on its own without inversion, but this approach
does not provide the most detailed view of the subsurface and can be misleading under certain
conditions. Because of its efficiency and quality, most oil and gas companies now use seismic
inversion to increase the resolution and reliability of the data and to improve estimation of rock
properties including porosity and net pay.
There are many different techniques used in seismic inversion, these can be roughly grouped
into two sets of categories: pre-stack vs. post-stack, and seismic resolution vs. well log resolution.
The combination of these categories yields four technical approaches to the inversion problem,
and the selection of a specific technique depends on the desired objective and the characteristics
of the rocks in the subsurface.
All modern seismic inversion methods require seismic data and a wavelet estimated from the
data. Typically, a reflection coefficient series from a well within the boundaries of the seismic
survey is used to estimate the wavelet phase and frequency. Accurate wavelet estimation is
absolutely critical to the success of any seismic inversion; G&W utilizes a Bayesian type wavelet
extraction named Wavelet derivation.
Once the wavelet is identified, seismic inversion computes a synthetic log for every seismic trace.
To ensure quality, the inversion result is convolved with the wavelet to produce synthetic seismic
traces that are compared to the original seismic