SubFace matrix-fracture transfer function: Improved model of gravity drainage/imbibition

Ahmad Abushaikha, Olivier R. Gosselin

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)


Gravity is a major recovery mechanism of naturally fractured reservoirs, where fracture gas drains matrix oil until equilibrium is reached with the capillary forces (wrt fluid densities, matrix gas capillary pressure and block height). The challenge of modelling gravity drainage in dual-medium simulation is to match the final maximum recovery, using integrated pseudo-capillary pressure curve, and the correct recovery kinetics. The paper suggests an approach to improve the simulation of the recovery kinetics in gravity drainage by dividing the matrix block for the fluid transfer function in two specific parts: saturation front part (SFP) and initial state part (ISP). As the invading gas enters the matrix the SFP and ISP areas increase and decrease respectively, until the final recovery is reached at equilibrium point. The contributions from each part are summed up to equal a mass conservation equation at each time step for each matrix cell. Properties of SFP depend on the invading fluid saturation and ISP hold the initial state properties, hence its name. This SubFace formulation can be implemented in flow simulator for reservoirs exhibiting a dual-medium behaviour. Our SubFace Transfer Function approach (SF), performs well versus not only conventional transfer functions (Kazemi, Gilman), but also versus two improved ones: Quandalle-Sabathier, and Lu-Blunt (non-Warren-Root General Transfer Function) in matching the results of fine-grid single-medium models under various parameters (capillary pressure, matrix shape and mobility). We also tested SF in mixed-wet water-oil system to assess its capability of modelling gravity and capillary imbibition. This new formulation improves dual-medium simulations of fractured reservoirs with an accurate representation of matrixfracture exchanges, and better reserves assessment and reservoir management.

Original languageEnglish
Title of host publicationSociety of Petroleum Engineers - EUROPEC/EAGE Conference and Exhibition 2009
PublisherSociety of Petroleum Engineers
ISBN (Print)9781613994276
Publication statusPublished - 1 Jan 2009
Event2009 SPE EUROPEC/EAGE Annual Conference and Exhibition - Amsterdam, Netherlands
Duration: 8 Jun 200911 Jun 2009


Other2009 SPE EUROPEC/EAGE Annual Conference and Exhibition


ASJC Scopus subject areas

  • Geotechnical Engineering and Engineering Geology
  • Geochemistry and Petrology

Cite this

Abushaikha, A., & Gosselin, O. R. (2009). SubFace matrix-fracture transfer function: Improved model of gravity drainage/imbibition. In Society of Petroleum Engineers - EUROPEC/EAGE Conference and Exhibition 2009 Society of Petroleum Engineers.