Technical Paper

Rock Physics Driven Inversion: The Importance of Reservoir Characterization Workflow

Written by: Michele Kemper, Ikon Science

Michel Kemper proposes a reservoir characterization workflow that spans modelling, processing, and quantitative interpretation within a rock physics driven framework (not a mere attribute algorithm) and provides a practical guide with some pitfalls to avoid.

Seismic inversion is the process of converting seismic reflectivity data to rock property information ranging from band-limited acoustic impedance (simplest) to petrophysical properties such as Vshale, porosity, and water saturation (most complex). From this definition it would appear that well data is not used; in practice, well data is used extensively in the inversion process, and this will be detailed in this paper, which consists of three parts:

• It is important to ensure that both seismic and well data are optimally conditioned prior to the inversion process, and some typical techniques will be shown.
• A rock physics study illustrates the need to (a) determine what the end product of an inversion project should be (bearing in mind the objective of this study), and (b) whether it is feasible to achieve this with the data available (noise, resolution, etc).
• A wide selection of inversion algorithms will be split into various categories and discussed in some detail.

Lastly, inversion is a tool, and not an end in itself. It can be used to good effect in reservoir characterization (from exploration to reservoir monitoring), and in this paper some techniques will be listed. A full discussion is outside the scope of this article. In practice the above workflow is not linear, and some iteration is required. Some examples will be shown in the text.

Published in First Break, Volume 28, October 2010