Introducing Ji-Fi - A New State-of-the-art Seismic Inversion System

There are many different ‘flavours’ of model-based Simultaneous Inversions, but they all have familiar shortcomings, eg…

1. The low frequency background model is a compromise across the facies encountered and is therefore difficult to determine. Ask yourself, what is the overall (low frequency) Acoustic Impedance value at an undrilled location? You can make some inferences from existing wells, but it remains largely guesswork.
2. When we are far away from seismic energy (typically generated by a transition from one facies to another) the impedance trends back to that 1 low frequency model, and we end up with a ‘neither sand nor shale’ impedance value.

The phrase above “typically generated by a transition from one facies to another” is a crucial one. Facies can be seen as discrete quantities, and as seismic energy is typically generated when transitioning from one facies to the other, the seismic inverse problem must contain a discrete element in it’s formulation. In other words, only inverting to impedance (continuous quantities) as done to date, does not really capture ths physics of the inverse problem.

In this paper we introduce is a joint discrete (facies) / continuous (impedances) formulation, which gives superior results as shown in a case study.