Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS

Methodology for stochastic realisations of matrix-fracture systems and upscaling of natural fractures and reservoir properties for coals

This is an operational methodology of characterizing static and dynamic reservoir properties as they apply to ECBM recovery. The particular structure of coal (fractured media) made of macro and micro fracture features obliges us to consider the microscopic and macroscopic scale in order to understand (and thus simulate) methane production and furthermore CO2 adsoption.

More classical methods could be applied to CBM production. Yet, a true understanding of the adsorption/diffusion mechanism of CH4 and CO2 as well as the diffusional effects taking place within the matrix (at small scale) needs an accurate understanding of the cleat system at the small scale. It is our ambition to show that from this scale one can proceed through a series of steps leading to an accurate petrophysical numerical (reservoir size cells) assignation at the inner-well scale. By accurate we mean that values assigned minimize the inherent errors due to up-scaling but above all are representative.

The basis of the approach is the assumption that the geometry of the cleat system (described statistically) at the small scale can serve to generate a realistic network of cleat features at the numerical size scale (ex. 100m). Once that done, one can generate within this unitary volume a series of petrophysical values (typically K and PHI) at will, through up-scaling, thus creating a petrophysical database. Once this database used in conjunction with logs, more classical characterization methods could then be used.

Reported by

Institut Francais du Petrole
Reservoir Engineering Department, BP 311, 1-4 Avenue de Bois-Preau
92852 Rueil Malmaison
See on map