ABSTRACT: Well Synthesis : a new tool for well based reservoir characterization

Rebelle, Michel , ELF Exploration Production, Pau, France

Calculation of OOIP and modeling of fluid flows requires knowledge of the petrophysical values which characterize both rock and fluid under initial conditions or later during exploitation. These values are determined while taking into account constraints from sedimentary and/or diagenetic processes. They are then feeded to the gridded geological model. To be of sufficient quality, the reservoir model not only requires a reliable geological model but also needs rules governing the distribution of the main facies with their associated petrophysical properties.

Well Synthesis provides a coherent set of probabilistic data to set up reliable reservoir engineering models.

Improvement of well based reservoir characterization relies on optimization and coherence of geological, petrophysical and log data acquired at different scales. It requires definition of correspondence rules between geological and petrophysical studies and calls for notions of probability allowing uncertainty estimation.

The Well Synthesis describes and records the cored interval, preserving data of different nature. Data are calibrated, corrected, validated and interpreted according to the user. Extrapolation of geological and petrophysical informations is derived from cores to the uncored zone, by well logs.

Several tools have been used to facilitate the integrated approach: WELLCAD^© software (records and quantifies core data), Petrophysical Groups (create petrophysical sub-sets for reservoir, Petrophysical Log (extrapolates petrophysical characteristics of the cored interval), Data matching (optimizes the classification and matching processes between logs and core data), Searching for correspondence rules through STATILOG^© software (qualifies and quantifies relationships between variables).

AAPG Search and Discovery Article #90913©2000 AAPG International Conference and Exhibition, Bali, Indonesia