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“Underground storage of Hydrogen in porous geological media”

Underground Sun Storage

European Workshop on Underground Energy Storage|

Markus Pichler | 2019 11 07

2

RAG Austria AG

Company Profile and

Vision• Among leading technical Underground

Gas Storage Operators

• State of the art facilities

• Storage volume 66 TWh (6bcm)

• Unload capacity 30 GW

• Follow the vision to serve the renewables with our existing assets by constant improvement and innovation

2030+ residual scenario for electricity in AT

+ 12.000 MW lasting for months

3

- 8.000 MW lasting for months

+ 12.000 MW lasting for months

INPUT data: 2030+ vs. 2017 @15 minute intervals:• Demand: +30% (~63 to 81 TWh/a)• RES generation : Wind x3, Solar x20, Hydro x1 (~ 41 auf 80 TWh/a)

=> Big scale seasonal storage needed

European Potential for Wind Energy Generation

4European Workshop on Underground Energy Storage| Markus Pichler | 2019 11 07

European Potential for Solar Energy Generation

5European Workshop on Underground Energy Storage| Markus Pichler | 2019 11 07

Motivation• Gas Storage is Energy Storage

• Gas Storage is ‘invisible‘ and ‘available on demand‘-Energy

• Gas has an existing infrastructure in many regions of the world

• Gas can be greened from 0-100% without changing the system

Goals of the Project• Demonstration of Storability of renewable gases in Gas Storage facilities

• Research on effects of 10% hydrogen admixtures in existing Gas Storage Facilities

Partners

Development of the Underground Sun Storage Project

European Workshop on Underground Energy Storage| Markus Pichler | 2019 11 07 6

Project

WP

5: M

ater

ials

an

dC

orr

osi

on

WP 1: Project ManagementW

P 2

Geo

chem

istr

y an

d R

eact

ive

Tran

spo

rt m

od

elli

ng

WP

3: M

icro

bia

l P

roce

sses

in

Hyd

roge

n E

xpo

sed

R

eser

voir

s

WP

4: D

emix

ing

of

Nat

ura

l Gas

an

d

Hyd

roge

n

WP

6: M

emb

ran

e

Tech

no

logy

WP

9: R

isk

Ass

essm

ent

and

Life

Cyc

le A

sses

smen

t

WP

10

: Eco

no

mic

and

Lega

l An

alys

is

WP 7: Design and Construction of Testbed

WP 8: Testbed Operation

European Workshop on Underground Energy Storage| Markus Pichler | 2019 11 07 7

Physical Parameters

• HP3A is very small and isolated

• Field experiments at reasonable costs and risks

• Conditions comparable to commercial RAG storage facilities

• High Permeability (up to 600 MD) Average Porosity (25%)

• Water Saturation (~30 %) No active Aquifer

Volumetrics

• GIIP ~6,15 MMNm³ net. Production ~4,45 MMNm³

• 1,22 MMNm³ Gas Mixture 115.444 Nm³ Hydrogen

• Pressure Range Reservoir (34 – 78 Bar(a))

• Temperature 39,5°C

Test Field Key Data

8

European Workshop on Underground Energy Storage| Markus Pichler | 2019 11 07


Subsurface Aspects

9

Open Questions from the Literature

Are the different materials in a gas storage facility resistant against hydrogen?

Is the tightness of the subsurface reservoir also given for hydrogen?

How does the hydrogen move in the subsurface?

Does the hydrogen change the chemical equilibrium of the reservoir?

Does hydrogen react with microbes in the reservoir?


Material Behaviour

10

• Steel and cement samples tested under lab and field conditions• Cement samples show signs of

calcification in blind and hydrogen samples

• Steel samples show no signs of embrittlement or significant reduction of strain to rupture

• Elastomers where tested only in the field

• Visual observation shows no significant changes

• Changes in mass and volume comparable to gas industry standards

• Further investigation in follow up project (USC)

Reaction Seam


Well and Reservoir Tightness

11

• Well• No observation of hydrogen in the

annulus

• No degradation of tubing or casing (USIT)

• No detection of gas migration in the well cementation (CBL)

• Rubber elements of packers where unchanged

• Reservoir• Permeability of hydrogen and methane

in the cap rock are in the same order of magnitude

Permeability [m²] Cap Rock

Formation Core Methane Hydrogen

A2 2.1 10-18 2.3 10-18

3 2.5 10-18 2.7 10-18

B1 8.5 10-19 8.2 10-19

3 3.2 10-18 1.9 10-18

< >

SSSV an hydraulic

operation line

3 1/2“ VAGT

Superior (VÖST)

Surface Tubing

2 7/8“ VAGT

Superior (VÖST)

Production Tubing

2 3/8“ VAGT

Superior (VÖST)

Production Tubing

Hydraulic Packer

Water Sampler lost

during 1st sampling

session

Perforations at 1150 MD

Formation: HP 3a

Cementation of Gas

Well

Annulus filled with KCl

Water and Corrosion

Inhibitor


Diffusion

12

• Only relevant for gas phase• Hydrogen diffusion in water saturated

porous media 10-4 – 10-5 m²/a

• No De- Mixing of gas during Shut In (Diffusion forces stronger then gravimetric effects)

• Changes in withdrawn gas due to• Diffusion?

• Dispersion?

• Dissolution?

• Chemical Reactions?

• Conversion?

0 5 10 15 20 25 30 35 40 45 50 5512

12.25

12.5

12.75

13

ratio top

lin trend top

ratio bottom

lin trend bottom

Reactor 10 bar

week

Rat

io C

H4/H

2

0

2

4

6

8

10

12

-20,000 180,000 380,000 580,000 780,000 980,000 1,180,000

Hyd

rog

en

Co

ncecn

trati

on

%

Working Gas Volume [Nm³]

Share of hydrogen in the gas versus working gas volume

Hydrogen Concentration Withdrawal

Hydrogen Concentration Injection


Diffusion

13

• Further equilibration of hydrogen during long time shut in (no sudden chemical reactions)

• Further experiments are conducted in the follow up project


Dispersion

14

• Break through experiments over 7 meters of porous medium

• Hydrogen is slightly faster than methane

• Effect is independent of flow speed

• Effect is canceled out in wet environment

0%

20%

40%

60%

80%

100%

120%

7500 8000 8500 9000 9500 10000 10500 11000

Shar

e [

Vo

l%]

Time [sec]

Injection of the Gas Mixture

Methan 20 Bar 80%

Wasserstoff 20 Bar 20%

0%

20%

40%

60%

80%

100%

120%

5000 5200 5400 5600 5800 6000 6200 6400 6600 6800 7000

Shar

e [

Vo

l%]

Time [sec]

Withdrawal of the Gas Mixture

Methan 20 Bar 80%

Wasserstoff 20 Bar 20%


Dissolution

15

• Dissolution of gas mixture was observed in the lab

• Literature gives a wide range of possible values for hydrogen dissolution in brines (0,8-10 % of injected volume)

• Time dependent process (equilibration)

• Pressure dependent => can be partly recovered

• Kinetics and volume need further research (USC)

0

2

4

6

8

10

12

-55,000 45,000 145,000 245,000 345,000 445,000

Shar

e o

f H

2/C

O2

[vo

l. %

]

Working Gas Volume

Development of Gasmixture

Hydrogen Injection

CO2 Injection

Hydrogen Production

CO2 Production


Reservoir Changes

16

• 12 months flow through experiments conducted at DBI with 25% and 75% of H2 in CH4

• Permeability changes due to clay swelling confirmed in blind samples

• No dissolution or precipitation observed on micro scale (thin sections)

• Permeability changes in the reservoir are comparable to common storage operations

0

200

400

600

800

1000

1200

1400

0

500

1,000

1,500

2,000

2,500

3,000

3,500

4,000

4,500

5,000

10.10.2006 22.02.2008 06.07.2009 18.11.2010 01.04.2012 14.08.2013 27.12.2014 10.05.2016 22.09.2017 04.02.2019

Vo

lum

e P

rod

uce

d [

Nm

³]Ta

use

nd

e

Date

Permeability Development over Reservoir Livetime

GP Net of HP3A

Permeability

Wasserpermeabilität

kw [m²]

Gaspermeabilität

kwg [m²]

Monate vor nach vor nach

2 2.77 10-14 2.86 10-14 2.43 10-13 2.31 10-13

3 5.55 10-14 3.16 10-14 2.17 10-13 2.57 10-13

6 4.07 10-14 3.75 10-14 1.60 10-13 1.45 10-13

9 3.87 10-14 2.58 10-14 1.31 10-13 1.11 10-13

12 2.59 10-14 7.19 10-14 1.95 10-13 1.06 10-13


Conversion

17

• No H2S was measured

• Acetate traces where found in the water samples

• No evidence of iron reduction

• Confirmed in Lab and Field-experiments• Roughly stoichiometric pressure drop

• Change of initial microbial consortia towards a higher population of methanogenic archaea

• Negative isotopic value shift

0.00

0.05

0.10

0.15

0.20

0.25

0 200000 400000 600000 800000 1000000 1200000

Car

bo

n D

ioxi

de

CO

nce

ntr

atio

n [

%]

Working Gas Volume [Nm³]

Carbon Dioxide Concentration during Storagecycle

Carbon Dioxid Injection

Carbon Dioxid Withdrawl

36.5

37

37.5

38

38.5

39

39.5

40

42,300 42,400 42,500 42,600 42,700 42,800 42,900 43,000

Tem

pe

ratu

re in

[°C

]

Date

Temperature Development

Temperature Development 2014

Temperature Development 2016

Temperature ab 01.12.16

Changes in microbiology

European Workshop on Underground

Energy Storage| Markus Pichler |

2019 11 07

18


Underground Sun Storage

19

• Renewable Energy can be stored as Hydrogen in underground gas reservoirs.

• 10 % share of H2 tested

• Project confirmed scale up potential to RAGs commercial facilities

• Open: Assignability to other geological reservoir settings

• Key Parameters Identified

• 100 % Hydrogen in natural gas reservoirs is the next development objective

• https://www.underground-sun-storage.at/

Power (Strom)

https://www.underground-sun-storage.at/

European Workshop on Underground Energy Storage | Markus Pichler | 2019 11 07

• Further research on diffusion is needed (USC)

• Dissolution of hydrogen into the reservoir brine is still not fully understood (external)

• Microbial activity throughout the reservoir needs further investigation (USC)

• Models to predict chemical and biological behavior of hydrogen bearing reservoirs are still not market ready and need further development and data (open)

• Rubber seals and elastomers still need further investigation (USC)

• Movement of hydrogen in the reservoir should be tested over longer distances. (USC)

Open Questions

20

Convert a one way industry into a sustainable cycle industry



2019 11 07

21

In-situ Field Experiments


Energy Storage| Markus Pichler | 2019

11 07

22

• Construction work finished

• Commissioning finished

• Batch experiments ongoing

• First Batch finished 03/2019

• Second Batch finished 07/2019

• Injection third Batch finished 09/2019

• Second well – May /2019

• Cycle Experiments till end of 2020

Scientific Preparation

23

• Further Research on microbial conversion in the Lab• Gas mixtures with up to 40% of

hydrogen

• Simulation of biomass development in the subsurface

• Material testing of steels, cements and elastomers in CO2/H2 atmospheres under elevated pressure and temperature conditions



2019 11 07

Conclusion

24

• State of the art underground gas storage facilities are

essential for Europe´s security of energy supply

• Increase of erratic renewable energy generation and

the integration of natural gas and electricity markets

in turn will generate additional demand in seasonal

and high-capacity large scale storage options

• Underground Sun Storage as well as Underground

Sun Conversion technology can solve the problem of

seasonal power storage

• Generation of renewable natural gas closes a

sustainable natural carbon cycle

• Integration of renewable gas combines the benefits

from classical natural gas infrastructure and the

sociopolitical target of renewable energy supply



2019 11 07

Contact

[email protected]

T +43 (0)50 724-5346

RAG Austria AG

Schwarzenbergplatz 16

A-1015 Vienna

www.rag-austria.at

www.underground-sun-conversion.at

Reservoir Engineer Subsurface Storage Development

Markus Pichler

Project Partners:

Thank YouForYour Attention

http://www.rag-austria.at/

http://www.underground-sun-conversion.at/

underground sun storage - energnet.eu · rag austria ag company profile and vision • among...

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