Understanding Oil and Gas Flow Mechanisms in Shale Reservoirs Using SLD–PR Transport Model

Xiukun Wang, James J. Sheng

Research output: Contribution to journalArticle

11 Scopus citations

Abstract

More and more attention has been paid to the oil and gas flow mechanisms in shale reservoirs. The solid–fluid interaction becomes significant when the pores are in the nanoscale. The interaction changes the fluid’s physical properties and leads to different flow mechanisms in shale reservoirs from those in conventional reservoirs. By using a Simplified Local Density–Peng Robinson transport model, we consider the density and viscosity profiles, which result from solid–fluid interaction. Gas rarefaction effect is negligible at high pressure, so we assume it is viscous flow. Considering the density- and viscosity-changing effects, we proposed a slit permeability model. The velocity profiles are obtained by this newly established model. This proposed model is validated by matching the density profile and velocity profile from molecular dynamic simulation. Then, the effects of pressure and pore size on gas and oil flow mechanisms are also studied in this work. The results show that both gas and oil exhibit enhanced flow rates in nanopores. Gas-phase flow in nanopores is dominated by the density-changing effect (adsorption), while the oil-phase flow is mainly controlled by the viscosity-changing effect. Both gas and oil permeability quickly decrease to the Darcy permeability when the slit aperture becomes large. The results reported in this work are representative and should significantly help us understand the mechanisms of oil and gas flow in shale reservoirs.

Original languageEnglish
Pages (from-to)337-350
Number of pages14
JournalTransport in Porous Media
Volume119
Issue number2
DOIs
StatePublished - Jun 13 2017

Keywords

  • Enhanced permeability factor
  • Oil and gas flow mechanism
  • Peng Robinson EOS model
  • Shale reservoirs
  • Simplified Local Density model

Fingerprint Dive into the research topics of 'Understanding Oil and Gas Flow Mechanisms in Shale Reservoirs Using SLD–PR Transport Model'. Together they form a unique fingerprint.

  • Cite this