Dynamic fmuid connectjvity during steady- state multjphase fmow in a - - PowerPoint PPT Presentation

Dynamic fmuid connectjvity during steady- state multjphase fmow in a sandstone

Catriona Reynolds, Hannah Menke, Matuhew Andrew, Martjn Blunt & Sam Krevor Proceedings of the Natjonal Academy of Science (2017) 114:31, 8187-8192 Department of Earth Science & Engineering, Imperial College London, UK SPE London Evening Meetjng, 30th January 2018

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Importance of fmuid fmow for geologic CO2 storage

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Conceptual models of two-phase fmow

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Ganglion dynamics and connected pathway fmow: Avraam & Payatakes (1995) JFMech, 293: 207-236

• Conceptual models of two-phase fmow have been used to justjfy

the multjphase extension to Darcy’s Law

• Observatjons from simple, model pore spaces suggest two phase

fmow occurs via separate, stable channels

• As the capillary number increases, the non-wetng phase breaks

into discrete ganglia which are advected through the pore space by the non-wetng phase

Capillary number increasing

ui = - kr,ik m

i

ÑF i

Improvements in micro X-ray CT scanning are providing observatjons of new fmow behaviour

4 `Droplet fragmentatjon’

Pak et al. (2015), PNAS 112(7): 1947-1952

Drainage event during a capillary pressure change

Andrew et al. (2015), Trans Porous Med 110(1): 1-24

Experimental Aim: observe rate-dependent, two-phase, steady-state fmow and the pore scale

Connected pathway

Ganglia fmow

Datua et al. (2014), Physics of Fluids, 26.

• Low capillary numbers (10-8 <Ca<10-5)

representatjve of subsurface fmow conditjons (Ca<10-6), mostly below the threshold for pore-scale ganglion motjon

• Steady-state co-injectjon
• Constant fractjonal fmow
• Constant fmuid propertjes (viscosity,

interfacial tension

• Cross Caw-Canw space using total fmow

rate.

• Look for a transitjon in fmow behaviour

at a critjcal capillary number 5

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Fluid Propertjes

Non-wetng phase N2 Wetng phase Brine (25 wt% KI) Conditjons 50°C, 10 MPa

Rock Propertjes

Rock type Bentheimer sandstone (>98% quartz) Permeability 2000 mD Porosity 20%

Experimental set-up

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Imaging using fast synchrotron X-ray CT at Diamond Light Source

• Non-destructjve

imaging technique

• 3D images with a

voxel size of 3.6 microns were acquired every 43 s

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Image processing

300 microns

qT [ml/min] Exp tjme [mins] Pore volumes Saturatjon

• f N2

0.04 29 15 35.8% 0.3 29 51 34.0% 1.0 29 172 35.4% 0.02 44 15 27.4% 0.1 35 21 22.5% 0.3 45 80 30.2% 0.5 42 124 32.1%

• 1 scan every 45 seconds
• 30-60 3D images per experiment

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Steady state saturatjon

FLOW 10

Time sequence profles of saturatjon confrm steady state

Increasing fmow rate/capillary number

40 μm 150 μm 3.5 mm

Ganglia size distributjon

4mm 11

• Percentage of small ganglia increases with fmow rate
• Percentage of large ganglia decreases with fmow rate

 N2 becomes less connected 12

Ganglia size distributjon

Stable connected pathway?

FLOW 13

Stable connected pathway?

FLOW 14

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0.02 ml/min 0.04 ml/min

Stable connected pathway?

Ganglia at high fmow rate/ high Ca

FLOW 16

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Dynamic connectjvity

Dynamic connectjvity: a single fmow regime?

Connected N2 from inlet to

• utlet

Disconnected ganglia only 18

No connected pathways Intermituent connected pathways

Connected pathway Ganglia fmow Dynamic connectjvity

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• Connected non-wetng phase pathways form only at low capillary numbers but are not stable
• Transient connectjons transport the non-wetng phase between statjc ganglia where the rate and

number of connectjons and disconnectjons increases with increasing fmow rate or capillary number

• At the contjnuum scale the conductance of a phase is governed by the entjre volume that it
• ccupies, even intermituently,.

Local rearrangements of the pore occupancy allow fmow sporadically, analogous to the stop-and-start of cars on roads controlled by traffjc lights.

Thank you

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Multjphase fmow characteristjcs of heterogeneous rocks from CO2 storage reservoirs in the United Kingdom

Catriona Reynolds, Martjn Blunt & Sam Krevor Water Resources Research (2018), Accepted Manuscript, doi:10.1002/2017WR021651 Department of Earth Science & Engineering, Imperial College London, UK SPE London Evening Meetjng, 30th January 2018

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Replotued from Bachu & Bennion (2008). Efects of in- situ conditjons on relatjve permeability characteristjcs

• f CO2-brine systems. Environ Geol 54: 1707–1722

Reynolds & Krevor (2015). Characterizing fmow behavior for gas injectjon: Relatjve permeability of CO2-brine and N2-water in heterogeneous rocks. Wat. Res. Res. 51, 12, 9464-9489

Reservoir conditjons afect relatjve permeability because of the varying role of rock heterogeneity

All rocks are heterogeneous

• And thus control relatjve

permeability

• Larger fmow potentjal can

support larger capillary pressure gradients

[kPa]

Virnovsky et al. (2004) Transport in Porous Media 54: 167- 192

Small heterogeneitjes can lead to large variatjons in saturatjon

During drainage: Capillary number decreases at higher fractjonal fmow of CO2 During imbibitjon: Capillary number increases at higher fractjonal fmow of water

Reynolds, Krevor (2015) Wat. Res. Res., doi:10.1002/2015WR018046

Test the impact by performing experiments under high fmow potentjal (viscous limited) and low fmow potentjal (capillary limited)

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• Bunter sandstone
• Reservoir conditjons (53°C,

13 MPa, 1 mol NaCl kg-1

• Two CO2-brine steady state

drainage and imbibitjon relatjve permeability tests

• One at low fmow rate

(capillary limited) and one high fmow rate (viscous limited)

Applied to real reservoir systems from the UK North Sea

Nc

Drainage Imbibition

Sw

Imbibition Drainage

3 30 0.3 0.2 0.4 0.6 0.8

B3 B4 B5 B6

Sw 1

High flow rate qT = 20 ml min-1 Low flow rate qT = 0.2 ml min-1

Nc

Drainage Imbibition

Sw

Imbibition Drainage

3 30 0.3 0.2 0.4 0.6 0.8

B3 B4 B5 B6

Sw 1

High flow rate qT = 20 ml min-1 Low flow rate qT = 0.2 ml min-1

Nc

Drainage Imbibition

Sw

Imbibition Drainage

3 30 0.3 0.2 0.4 0.6 0.8

B3 B4 B5 B6

Sw 1

High flow rate qT = 20 ml min-1 Low flow rate qT = 0.2 ml min-1

Nc

Drainage Imbibition

Sw

Imbibition Drainage

3 30 0.3 0.2 0.4 0.6 0.8

B3 B4 B5 B6

Sw 1

High flow rate qT = 20 ml min-1 Low flow rate qT = 0.2 ml min-1

Nc

Drainage Imbibition

Sw

Imbibition Drainage

3 30 0.3 0.2 0.4 0.6 0.8

B3 B4 B5 B6

Sw 1

High flow rate qT = 20 ml min-1 Low flow rate qT = 0.2 ml min-1

Nc

Drainage Imbibition

Sw

Imbibition Drainage

3 30 0.3 0.2 0.4 0.6 0.8

B3 B4 B5 B6

Sw 1

High flow rate qT = 20 ml min-1 Low flow rate qT = 0.2 ml min-1

Nc

Drainage Imbibition

Sw

Imbibition Drainage

3 30 0.3 0.2 0.4 0.6 0.8

B3 B4 B5 B6

Sw 1

High flow rate qT = 20 ml min-1 Low flow rate qT = 0.2 ml min-1

Nc

Drainage Imbibition

Sw

Imbibition Drainage

3 30 0.3 0.2 0.4 0.6 0.8

B3 B4 B5 B6

Sw 1

High flow rate qT = 20 ml min-1 Low flow rate qT = 0.2 ml min-1

Nc

Drainage Imbibition

Sw

Imbibition Drainage

3 30 0.3 0.2 0.4 0.6 0.8

B3 B4 B5 B6

Sw 1

High flow rate qT = 20 ml min-1 Low flow rate qT = 0.2 ml min-1

Nc

Drainage Imbibition

Sw

Imbibition Drainage

3 30 0.3 0.2 0.4 0.6 0.8

B3 B4 B5 B6

Sw 1

High flow rate qT = 20 ml min-1 Low flow rate qT = 0.2 ml min-1

Efects persist at larger scales: Li and Benson (2015) AWR; Meckel, Bryant, Ganesh (2015) IJGGC Upscaling techniques established for efgectjve relatjve permeability down to the core scale: Rabinovich, Ithisawatphan, Durlofsky (2015); Lohne, Virnovsky, Durlofsky (2006) SPEJ; Pickup and Sorbie (1996) SPEJ

Reynolds, Krevor (2015) Wat. Res. Res., doi:10.1002/2015WR018046

For buoyantly driven CO2 plumes or other low potentjal fmows, the impacts are present in the fjeld

100 10–1 10–2 10–3 10–4 0.2 0.4 0.6 0.8 1

0.2 0.4 0.6 0.8 1 10-4 10-3 10-2 10-1 100

B1, B3 B2, B4 B5 B6

Sw kr

0.2 0.4 0.6 0.8 1 0.2 0.4 0.6

Initial CO2 saturation Residual CO2 saturation B7 B8

High fmow rate Low fmow rate

Small heterogeneitjes have a large impact at fmow rates observed in the reservoir

How do we characterise this? Can we incorporate it into modeling?

1.

Pressure, temperature, fmuids must match reservoir

2.

Multjple and low fmow velocitjes needed to cover parameter space

3.

Heterogeneity orientatjon in the core should afect fmow the same as in the reservoir

Limitatjons to performing core fmoods on heterogeneous rocks