This paper describes a new three-dimensional (3D), three-phase, multipurpose reservoir simulator. An extensive description is given of the dual-porosity facility . Three user-selected options available for computing the material transfers between matrix and fractures are developed and discussed. The most sophisticated option accurately accounts for the capillary, gravity, and viscous forces. A simplified thermodynamical package is also presented and examples are given.

MƒTHODOLOGIE RAPIDE ET EFFICACE POUR CONVERTIR LES IMAGES DE RƒSERVOIR A RAPID AND EFFICIENT METHODOLOGY TO CONVERT FRACTURED RESERVOIR IMAGES INTO A DUAL-POROSITY MODELBoth characterization and dynamic simulation of naturally-fractured reservoirs have benefited from major advances in recent years. However, the reservoir engineer is still faced with the difficulty of parameterizing the dual-porosity model used to represent such reservoirs. In particular, the equivalent fracture permeabilities and the equivalent matrix block dimensions of such a model cannot be easily derived from observation of the complex images of natural fracture networks. This paper describes a novel and systematic methodology to compute these equivalent parameters. copyright C 1998, Institut Français du Pétrole its validity and efficiency in dealing with field situations. A tensor of equivalent fracture permeability is derived from single-phase steady-state flow computations on the actual fracture network using a 3D resistor network method and specific boundary conditions. The equivalent block dimensions in each layer are derived from the rapid identification of a geometrical function based on capillary imbibition. The methodology was validated against fine-grid reference simulations with a conventional reservoir simulator. Then, a complex outcrop image of a sandstone formation was processed for demonstration purposes. This innovative tool enables the reservoir engineer to build a dualporosity model which best fits the hydraulic behavior of the actual fractured medium. METODOLOGêA RçPIDA Y EFICAZ PARA CONVERTIR LAS IMçGENES DE YACIMIENTOS FRACTURADOS EN MODELO DE DOBLE POROSIDADLa caracterizaci-n y la simulaci-n din ‡mica de los yacimientos naturalmente fracturados han aprovechado las ventajas derivadas de los importantes adelantos que han surgido durante estos oeltimos a-os. No obstante, el ingeniero de yacimientos sigue estando acuciado por la dificultad consistente en parametrar el modelo equivalente de doble porosidad utilizado para representar este gŽnero de yacimientos. B ‡sicamente, las permeabilidades de fractura equivalentes y las dimensiones del bloque matricial no se pueden deducir f ‡cilmente de la observaci-n de las im ‡genes complejas de redes naturales de fracturas. Se describe en el presente art'culo una tŽcnica, nueva y sistem ‡tica, para calcular estos par ‡metros equivalentes. Los resultados de su implementaci-n por medio de un software espec'fico demuestran su validez y su eficacia para el estudio de casos de campo. Un tensor de las permeabilidades de fractura se deduce de c ‡lculos de flujos estacionarios y monof ‡sicos en la red real de fracturas asimiladas a una red 3D de resistencia y sometido a condiciones l'mites espec'ficas. Las dimensiones del bloque equivalente en cada estrato se obtienen r ‡pidamente por identificaci-n de una funci-n geomŽtrica representativa de un desplazamiento capilar. La metodolog'a se ha validado por comparaci-n con las simulaciones de mallado fino, realizadas por medio de un simulador de ...

This paper was prepared for presentation at the 1999 SPE Annual Technical Conference and Exhibition held in Houston, Texas, 3–6 October 1999.