Kingdom 2021 will be out soon! We’ve been hard at work updating and enhancing both VelPAK and the Kingdom Seismic Inversion software. Here we focus on What’s New in Kingdom Seismic Inversion!
The New Inversion Validation Tab
The Kingdom Inversion Pre-Stack Analysis module has a new Inversion Validation tool, allowing fast and convenient comparison of logs with the inversion results. In addition to allowing comparison of elastic property volumes (such as Vp/Vs, Poisson’s ration & Young’s modulus) with the well log equivalents, scaling of volumes to petrophysical properties (porosity, Vsh, Sw, TOC etc.) can be performed. Cross-plotting between the well log and property volumes allows assessment of the match both visually and by cross-correlation.
For deviated wells the value can be set at the middle of the target reservoir interval to focus the comparison at the centre.
The left panel shows a cross-section of the volume with log in the middle and the middle graph compares the inversion result to the log and the LF (low frequency) Model.
The cross plot on the right takes the inversion results and the log (the two traces seen in the middle log) and calculates the correlation coefficient between the two curves. The correlation coefficient is calculated indicating the quality of inversion. The red line shows the 45 degree bisect line; showing where a perfect AI inversion with inverted AI matching the AI log exactly would lie.
If an Elastic Impedance volume is selected this will give a constant and scalar value depending on whether the EEI is positive or negative (in the EEI Correlation tab) to be used within Kingdom to produce a properly scaled porosity volume. It is dependent on a good inversion of AI and SI.
Estimated Porosity volume from scaled elastic impedance (after applying constant and scalar to EEI volume in Kingdom) is displayed here in Kingdom.
For improved results in the Simulated Annealing inversion, both for post-stack and pre-stack equivalents, the ability to extract a composite seismic trace along the borehole track has been added. This results in better estimated wavelets, and thus a better inversion result where wells are highly deviated. The option is found in the LogSeisMatch module under the “Trace Used for Inversion” menu.
The Simulated Annealing Inversions can now optionally output low-frequency acoustic impedance, shear impedance and density volumes as applicable, in addition to the inversion and synthetic results, if required. These volumes can be used as models in the next test run, saving time to re-parameterize jobs. They can also be used for cross-validation of inversion results in the new Inversion Validation tab.