Presented by: Philippe Rabiller
Domain: Formation Evaluation
Technology: Geolog™ Facimage™
Articles that state the difficulty of establishing an accurate and reliable relationship between porosity and permeability, in order to create a continuous permeability profile in wells, abound in the Petrophysical literature devoted to carbonate reservoirs. To try and alleviate this difficulty, new numerical methods or data mining techniques are often proposed. However, despite the necessity of interpreting data in terms of causation, those papers hardly discuss and explore, and even less so, explain, the origins of this difficulty. Therefore, questioning the ways in which these techniques are used is as legitimate as examining if they are really effective.
This presentation demonstrates how physical laws, established by Mercury Injection Capillary Pressure (MICP) experiments, explain why it is impossible to establish a reliable relationship between RCA porosity and permeability. Data mining techniques are not meant to try and reverse physical laws. However, as illustrated here, some of them, namely the MRGC-CFSOM and k-NN techniques, are very effective in exploring the geologic factors controlling the storage and flow properties of the porous network as measured by HPMI/MICP, so as to create a reliable continuous profile over un-cored logged intervals. We present the results obtained on 1052 HPMI/MICP measurements from 11 wells belonging to different fields and basins, supported by those obtained on several undisclosed data sets of greater size.
Philippe Rabiller is an independent consultant specializing in “descriptive petrophysics” and large, field or basin scale, formation characterization projects. A former geologist with Elf, he and his co-worker Shin-Ju YE designed the algorithmic processes and interpretation methods embedded in the Facimage™ and borehole imagery modules of the Geolog™ software. To further improve formation characterization (in terms of reservoir or seal properties) and saturation height modeling, he recently implemented and published an automated algorithmic method for the integration and interpretation of MICP measurements with all other core and log data. This method reconciles the permeability models proposed by Darcy, Poiseuille, Kozeny, Carman, Purcell, Swanson, Katz and Thomson, Pittman.
Philippe Rabiller is the author or co-author of 7 patents and 40 publications.