The leading depth conversion and seismic inversion software company Equipoise Software has announced the release of its seismic inversion software InSeis on the Petrel* package. Already well- established as part of IHS Markit’s Kingdom package marketed as Kingdom Seismic Inversion, InSeis is a powerful tool for converting seismic reflectivity data to acoustic impedance, an important attribute for structural interpretation and reservoir characterisation. Petrel data such as well log, horizons and seismic cubes are transferred to a specially formatted disk file by a Data Exchange Link, allowing InSeis to operate externally, so it does not tie up a Petrel* license when in use.
InSeis currently consists of two inversion modules – Coloured Inversion and Simulated Annealing inversion. Coloured Inversion is a fast and robust tool to convert seismic reflectivity data into relative impedance by shaping the seismic amplitude spectrum into log impedance spectrum. An automatically estimated phase value is then applied to the shaped spectrum to generate relative impedance.
Simulated Annealing inversion on the other hand inverts for absolute impedance from stacked seismic data using a global optimisation approach. Its distinctive advantage is that its solution doesn’t depend on an initial model because of its unique capability to move model parameters both uphill and downhill. The SA inversion algorithm is well constrained by a background model, hence significantly reducing the non-uniqueness problem.
Equipoise Software’s inversion package also comes with an advanced model generation tool HiDef which produces a low frequency macromodel compatible with geological structures, seismic processing velocity and well log data.
This model can be used as an initial model for SA inversion thus compensating the low frequency component missing in band-limited seismic data. SA inversion delivers wide-band absolute and relative impedance as well as S/N enhanced synthetic seismic data. Both of Equipoise Software’s inversion software packages have a seamless integration between different sub-modules including log calibration and wavelet estimation, and have built in comprehensive quality-control utilities at each stage of inversion. After inversion, the impedance data are immediately available for structure interpretation and reservoir characterisation in the Petrel* platform.
*Petrel is a Trademark of Schlumberger.