Flow Visualization & Pore Network Simulation of Immiscible/ Miscible Displacement with Gravity Domination M. Haghighi M. Haghighi09/09/09

Table of Contents EOR Process with Gravity Domination Darcy Law Is Not Enough Experimental Results Modelling Results Future Work

EOR Process with Gravity Drainage GAGDSAGD Downdip Gas Injection Updip Gas Injection Gas Injection In Fractured Reservoirs

CO2 GAGD (Jadhawar & Sarma)

SAGD

Downdip Gas Injection

Gravity Drainage In Fractured Reservoirs

Reservoir Simulation Reservoir Simulation Diffusivity Equation (Mass Balance and Darcy Equation) Relative Permeability Concept (Buckley- Leverett equation for immiscible displacement)

EOR Efficiency Microscopic Displacement Efficiency × Macroscopic Displacement Efficiency

Microscopic Displacement Efficiency Flow Mechanism at Pore Scale Pore Geometry Pore Structure WettabilityDispersionDiffusion

Macroscopic Displacement Efficiency Areal Sweep Efficiency Vertical Sweep Efficiency Large Scale Reservoir Heterogeneities Well Pattern

Darcy Law is not enough (at Pore Scale) Pore Scale Flow Mechanisms Film Flow Meniscus Movement Corner Flow Wettability Alteration Fluid Spreading

Darcy Law Is Not Enough (In Pore Network) Viscous Fingering Invasion Percolation Diffusion Limited Aggregation Fractal Characteristics

DLA

Lenormand et al.

Research Tools at Pore Scale Flow Visualization using Glass Micromodel Flow Visualization using Glass Micromodel Pore Network Simulation Pore Network Simulation

Glass Etched Micromodels 1) Preparing the pattern of porous media 2) Elimination of the protection-layer of the mirror 3) Covering the mirror with photo resist laminate 4) Exposing the covered mirror to UV light 5) Elimination of not-lightened parts using a developer 6) Etching the glass with HF 7) Fusing the etched glass with a plain glass

Experimental Set-up

Experimental Results

Pore Network Modeling Simple solution to the momentum equations in each pore throat. Mass conservation at each pore: 1.A discrete view of the porous medium (pores and pore throats) Pores provide volume & interconnectivity Pore throats provide resistance to flow. 2.Solution to various transport problems using conservation equations.

Solution of the Fluid Flow in the Network Fluid Flow Equations a) One Phase (Oil): a) One Phase (Oil): b) Two-Phase (Oil & Gas): b) Two-Phase (Oil & Gas): Nodes with Oil-Gas Front: P gas = Constant= P atm Continuity (Mass Balance) Eq. For Each Oily Node: Writing Continuity Eq. for all Nodes, We have a linear set of equations: Conductances: g =0.5GA 2 /μ, circular cross section g = GA 2 /μ, square cross section g = 3R 2 A/20μ, triangular cross section A t = πR 2, circular cross section A t = 4R 2, square cross section A t =R 2 /4G, triangular cross section Film Conductance:

Gas-Oil Displacement Generalization of Continuity Eq. for Different Fluid Configurations Example: If All Adjacent Nodes of Node i Are Oily Nodes: Example: If One of the Adjacent Nodes of Node i be Occupied by Gas: 3 4 Different Fluid Gonfigurations → 3 4 Different Continuity Equations

Pore Level Displacement Mechanisms 2-Phase Displacement Mechanisms a) Drainage a) Drainage b) Imbibition b) Imbibition c) Counter-Current Drainage c) Counter-Current Drainage 3-Phase Displacement Mechanisms 3-Phase Displacement Mechanisms a) Double Drainage a) Double Drainage b) Double Imbibition b) Double Imbibition

Model Assumptions ≈10 -6 → Viscous forces are negligible ≈10 -6 → Viscous forces are negligible ≈ 1609 > → Gravity forces are very important ≈ 1609 > → Gravity forces are very important

Experimental Results

Future Work Micible Co2 Flooding with Gravity Domination Using Glass-etched Micromodel and Pore network Modelling

Miscible Co2 Flooding with Gravity Domination Establishing Flow Visualization Lab Establishing Flow Visualization Lab Performing Miscible Displacement Tests Performing Miscible Displacement Tests Developing Pore Network Model for Miscible Displacement Developing Pore Network Model for Miscible Displacement Identifying Controlling parameters Performing Experimental in Core Scale Performing Process Optimization Upscaling

End Any Questions?