Gussow – Closing the gap III – Advances in Applied Geomodeling
You wish to learn more about a new workflow for Time-to-Depth Conversion which considers uncertainties in all aspects? Come and listen to David Garner presentation on behalf of Geovariances.
Proper Systemic Knowledge of Reservoir Volume Uncertainties in Depth Conversion
Thursday, October 11th, 2018
Hélène Binet (Geovariances, France), Pedro P. Correia (Geovariances, France), Nicolas Nosjean-Gorgeu (Neptune Energy, France), Didier Renard (Mines ParisTech, France), François Geffroy (Geovariances, France), Jean-Marc Chautru (Geovariances, France), David Garner (TerraMod, Canada).
Volumetric calculation is a common operation after performing time to depth conversion. It provides us with a measure of the volume of reserves we can expect from any given reservoir. This is, however, a process embroiled in uncertainties. Lack of hard-data, noisy seismic (particularly around faults), struggle in obtaining the most adequate local or global anisotropy model, variogram modeling, and, of course, the difficulty in finding the best methodology for spatialization. That is to say which algorithm to use to estimate (i.e. interpolate/extrapolate) the depth at any given XoY location in a time horizon. For each software package, there is usually one strong option available with any given number of parameters for a more complete customization. Further stochastic simulations are performed to characterize the uncertainty space. But using the technology developed within the research and development consortium UncerTZ, we could test a broad selection of different approaches. Calculating volumes over the results of each of these approaches we come to the conclusion that we obtain significantly different volumes. The problem is further complexify by the fact that many of these approaches perform very well under the most typical quality checking criteria. Given the economic importance of obtaining the most accurate possible number for reservoir volume, this leaves us in the precarious situation that committing to a single solution might indeed be analogous to committing to the wrong one. In this article, we will demonstrate the variability of the reserve volumes we obtain depending on approach and discuss possible solutions for this problem.