A fast screening tool for assessing the impact of poro-mechanics on fractured reservoirs using dual-porosity flow diagnostics

Lesly Gutierrez-Sosa, Sebastian Geiger, Florian Doster

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

Abstract

Accounting for poro-mechanical effects in full-field reservoir simulation studies and uncertainty quantification workflows is still limited, mainly because of their high computational cost. We introduce a new approach that couples hydrodynamics and poro-mechanics with dual-porosity flow diagnostics to analyse how poro-mechanics could impact reservoir dynamics in naturally fractured reservoirs without significantly increasing computational overhead. Our new poro-mechanical informed dual-porosity flow diagnostics account for steady-state and singlephase flow conditions in the fractured medium while the fracture-matrix fluid exchange is approximated using a physics-based transfer rate constant which models two-phase flow using an analytical solution for spontaneous imbibition or gravity drainage. The deformation of the system is described by the dualporosity poro-elastic theory, which is based on mixture theory and micromechanics to compute the effective stresses and strains of the rock matrix and fractures. The solutions to the fluid flow and rock deformation equations are coupled sequentially. The governing equations for fluid flow are discretised using a finite volume method with two-point flux-approximation while the governing equations for poro-mechanics are discretised using the virtual element method. The solution of the coupled system considers stress-dependent permeabilities for fractures and matrix. Our framework is implemented in the open source MATLAB Reservoir Simulation Toolbox (MRST). We present a case study using a fractured carbonate reservoir analogue to illustrate the integration of poro-mechanics within the dual-porosity flow diagnostics framework. The extended flow diagnostics calculations enable us to quickly screen how the dynamics in fractured reservoirs (e.g. reservoir connectivity, sweep efficiency, fracture-matrix transfer rates) are affected by the complex interactions between poro-mechanics and fluid flow where changes in pore pressure and effective stress modify petrophysical properties and hence impact reservoir dynamics. Due to the steady-state nature of the calculations and the effective coupling strategy, these calculations do not incur significant computational overheads. They hence provide an efficient complement to traditional reservoir simulation and uncertainty quantification workflows as they enable us to assess a broader range of reservoir uncertainties (e.g. geological, petrophysical and hydro-mechanical uncertainties). The capability of studying a much broader range of uncertainties allows the comparison and ranking from a large ensemble of reservoir models and select individual candidates for more detailed full-physics reservoir simulation studies without compromising on assessing the range of uncertainties inherent to fractured reservoirs.

Original languageEnglish
Title of host publicationSPE Reservoir Simulation Conference 2021
PublisherSociety of Petroleum Engineers
ISBN (Electronic)9781613997475
DOIs
Publication statusPublished - 19 Oct 2021
EventSPE Reservoir Simulation Conference 2021 - Virtual, Online
Duration: 26 Oct 2021 → …

Conference

ConferenceSPE Reservoir Simulation Conference 2021
Abbreviated titleRSC 2021
CityVirtual, Online
Period26/10/21 → …

ASJC Scopus subject areas

  • Geochemistry and Petrology
  • Modelling and Simulation

Fingerprint

Dive into the research topics of 'A fast screening tool for assessing the impact of poro-mechanics on fractured reservoirs using dual-porosity flow diagnostics'. Together they form a unique fingerprint.

Cite this