Note the Pre-Stack Inversion is only available as part of the Kingdom Seismic Inversion module and is not available on Schlumberger’s Petrel InSeis.
Pre-stack inversion can be used when post-stack inversion fails to sufficiently differentiate geologic features that have similar P-impedance signatures. It makes use of amplitude versus offset information and inverts offset gathers for P-impedance, S-impedance and density.
Kingdom PSI does not work on seismic gathers. Instead it works primarily with Angle Stacks and existing technology available to the user through existing post-stack SA tools (SA Inversion) to run for acoustic, shear impedances and density. The results are equivalent to those of simultaneous 3-parameter pre-stack inversion.
Click here to watch a webinar of the Pre-Stack Inversion [when it is available for public consumption].
More elastic parameters can be derived from Vp, Vs and density. These include Acoustic Impedance, Shear Impedance, Poisson’s ratio, Vp/Vs, Poisson’s Ratio, Lambda*Rho, Mu*Rho, Lambda/Mu, Young’s Modulus and Elastic Impedance (EEI).
Kingdom PSI then displays all the elastic logs and cross-plots any pair of elastic logs in either linear or logarithmic scales.
Pre-Stack Seismic Inversion takes the following seismic data:
- P and S wave reflectivity stacks (Rp and Rs) from Fatti’s 2-term AVO analysis
- The Intercept and gradient stacks from Shuey’s AVO analysis. These two stacks are then converted to Rp and Rs stacks
- Minimum 3 angle stacks, which are then converted to Rp and Rs or density stacks
Benefits of Kingdom Pre-stack Inversion:
- Elastic log analysis to identify targets
- Cross-plot any pairs of logs
- EEI and log correlation analysis
- AVO analysis on multiple angle stacks
- Cascaded and constrained inversion for AI, SI and density
- Wavelet estimation for P, S and density reflectivity volumes
- Elastic parameter transform to Poisson’s ratio, Young’s modulus etc.
- Mapping reservoir properties using polygons
- Estimate porosity, VSH, SW and TOC using EEI and log correlation
- Suitable for both conventional and unconventional reservoirs
- Simple to set up & easy to parametrize, and supports multi-CPUs
- Fully integrated with Kingdom project database as there is no data transfer time