Geothermal energy - PanTerra · Economic risk reduction of geothermal energy projects: Case study of the Delft Sandstone A.G. Vondrak, M.E. Donselaar, C.J.L. Willems, D.K. Munsterman,

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NAC 13

Economic risk reduction of geothermal energy projects:

Case study of the Delft Sandstone

A.G. Vondrak, M.E. Donselaar, C.J.L. Willems, D.K. Munsterman,

A.A. Van De Weerd and C.T.A.M. Leo

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Geothermal energy

• Green energy

• First project in 2007

• Costs 15 million

• Greenhouse heating

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Study objective

• Reduce economic risks for geothermal projects

– Reduce uncertainties of reservoir characteristics

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Geothermal energy in the Netherlands

• Doublets

• Closed system

• Injection and production well

• Six active doublets in the WNB

Reservoir

Heat exchanger

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West Netherlands Basin

• First doublet

• Cretaceous reservoir rocks

• Late Jurassic rifting

• Late Cretaceous inversion

Modified from Herngreen and Wong,2007

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Stratigraphic scheme West Netherlands Basin

• Four important members

• Delft Sandstone main target

• In whole WNB a dominant sandstone

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Nieuwerkerk Fm

• Fluvial deposits

• NW-SE trend

• Constrained by fault activity

• Occurs in all sub-basins

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Nieuwerkerk Fm

• Fluvial deposits

• NW-SE trend

• Constrained by fault activity

• Occurs in all sub-basins

HON sub-basin

PNA-GT sub-basin

VDB sub-basin

Structural high

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Cross section PNA-GT-02 VDB-GT-04 HON-GT-01

& -02 W E

Base Rijswijk

Base Upper North Sea Group

Base Chalk Group Base Niewerkerk Fm

Base Delft Sst?

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• Current knowledge from structural highs

• Architecture of the fluvial Delft Sandstone reservoir is difficult to predict

• Economic risk depends on well placement

Problem statement

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• Current knowledge from structural highs

• Architecture of the fluvial Delft Sandstone reservoir is difficult to predict

• Economic risk depends on well placement

Problem statement

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Stratigraphic correlations

• Biostratigraphical correlation: – Age

– Depositional environment

• Well correlations

• Seismic correlations

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Original hypotheses

Van Adrichem Boogaert & Kouwe, 1997

DeVault & Jeremiah, 2002

One continuous Delft Sst. in the WNB

No Delft Sst.

Thick, stacked channel complexes in the WNB

10km

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Preliminary dating results

VDB-GT- 04

Ap

tian

B

arre

mia

n

Hau

teri

vian

Va

lan

gin

ian

R

yaza

nia

n

Lower

Lower

Lower

Upper

Upper

Upper

Berkel

HON-GT- 01

PNA-GT- 01

PNA-GT- 02

Rijswijk

Delft

W E

Biostratigraphical analyses done by TNO D.K. Munsterman

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Well panel VDB-GT-04 HON-GT-01 PNA-GT-01 PNA-GT-02

Top Rodenrijs

Base Rodenrijs

Top Delft

Valanginian

Ryazanian

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Conclusion - hypothesis

• Not one Delft Sandstone

• Fluvial system stepped from one sub-basin to the next

PNA-GT-02 VDB-GT-04

Lagoonal

Terrestrial

HON-GT-01

Ryzanian

Valanginian

Barremien

Delft 1

Delft 3

Delft 2

Flood plain Delft 1

Floodplain Delft 3

Hauterivian

W E

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Geothermal implications

• Reduced uncertainties in reservoir characteristics important for economic risk reduction – Use reservoir characteristics from specific sub-basin

– Placement of doublets in NW-SE direction

Reservoir

Heat exchanger

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Next step

• Include new biostratigraphical data

• Include regional seismic interpretation

• Verify hypothesis with well data

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Thank you