Fluid Production for Geothermal Energy Grant Ferguson Dept. of Civil and Geological Engineering University of Saskatchewan
Some Acknowledgements… Students • David Phillips • Blake Woroniuk • Lotanna Ufondu • Joel Steeves • Britney Laturnus
Collaborators • Steve Grasby • Jennifer McIntosh
Roadmap • The opportunity • Potential for fluid production • Challenges including the race for porosity
The Western Canada Sedimentary Basin
Temperatures are known in the WCSB
Fourier’s Law qh = -κ dT/dx
Darcy’s Law qf = -K dh/dx
Over 20 billion m3 of water has been produced from the WSCB
Over 23 billion m3 of water has been injected into the WSCB
Injection wells operate at higher rates than production wells.
Direct-use for space heating is possible with at temperatures above 45°C [Rafferty, 2004; Lund, 2011], resulting in an outlet temperature of 30°C. Based on these criteria, the thermal power associated with each well is estimated with the following equation: Pt=Qf ρf cf ∆T Where: Pt is thermal power, Qf is fluid flow rate, ρf is fluid density and cf is fluid heat capacity. T is calculated assuming a geothermal gradient of 0.03 K/m
Most production wells do not produce sufficient amounts of water to be viable geothermal wells.
Roughly 50% of injection wells might be viable as geothermal wells (>100 kWt). A few hundred would produce > 1 MWt.
Injection tracks production of coproduced water in oil reservoirs
Oil production Water production Water injection -
Large injection capacity outside of depleted oil reservoirs
Just a Prairie Boy
The potash industry injects 30 million m3 of brine into the Deadwood and Interlake formations each year.
THE DEADWOOD
Copyright 2003-2009 Travis N. Wood
Depth to Deadwood (m)
Deadwood Temperatures (°C)
Deadwood Temperatures (°C)
Deadwood Temperatures (°C)
HEAT PUMPS
DIRECT USE
ELECTRICITY
Mosaic Belle Plaine
Very high injection rates possible in the Deadwood 100 L/s converts to ~ 15 MWth
Injection rates at Mosaic Belle Plaine
Similar systems have been operating in the Dogger aquifer, France for decades
From Lopez et al.,
So what’s the hold up here?
Permeability is a highly variable parameter.
Deep portions of the Deadwood may not support high capacity wells. Deadwood Formation permeability from DST
Deadwood Formation permeability from core
Deep portions of the Deadwood may not support high capacity wells.
Other considerations‌
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Wells in a Portion of the Canadian Bakken subsurface can
The be a crowded place…
The Race for Porosity
HVHF fluid FB/PW R FE UI AQ TARD UI AQ ER UIF AQ D AR UIT AQ ER UIF AQ
AQ U
ITA
EOR makeup water EOR
AQUIFE R
SWD
RD
REGION
OIL
AL FLO W
LEAKY WELLS
From McIntosh & Ferguson, In review
OIL
The Race for Porosity Geothermal wells
HVHF fluid FB/PW
EOR makeup water
EOR
RR FEE UUIIF AAQQ AARRDD UUITIT AAQQ EERR UUIFIF AAQQ DD AARR UUITIT AAQQ EERR UUIFIF AAQQ
AAQ AQUIFE QUU A R ER IITTA QUIF ARR D D
REGIONA L FLOW
OIL LEAKY WELLS
From McIntosh & Ferguson, in review
SWD
OIL
Redwater Field, Alberta
Wells
Facilities (Pipelines, Pump Stations, Batteries, etc)
Temperature • Reservoir temp: ~34 °C • Injected water is mostly produced water – 1.71 km3 produced vs 1.77 km3 injected
• Produced water stored on surface • Average annual temperature at Redwater: 1.6 °C • Assume mixing in entire reservoir – Final temp: 28.4 °C – Greater difference around wells
Estimated Temperature Changes
34°C
23°C
1°C
Induced Seismicity at Esterhazy, SK
Moving around large volumes of fluid may result in induced seismicity
Pros to developing geothermal energy in sedimentary basins: • High permeability • Availability of data Cons to developing geothermal energy in sedimentary basins: • Existing infrastructure and changes in temperature • Low temperatures Geothermal wells
HVHF fluid FB/PW R FE UI D AQ AR UIT AQ R
IFE
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IFE
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U AQ
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REGION A
L FLOW
From McIntosh & Ferguson, in review
EOR makeup water EOR
OIL
SWD
OIL