The document summarizes the future of geothermal development in Iceland. It discusses Iceland's increasing reliance on geothermal energy since 1940 and the goal to develop unconventional geothermal systems (UGS) at greater depths inside Iceland's volcanic zone. It provides examples of superhot geothermal systems like the IDDP-1 well in Krafla, which encountered a magma body at 2km depth. Lessons from IDDP-1 include the need for improved exploration, well design, and handling of harsh geothermal fluids. Upcoming IDDP-2 aims to further study superhot systems. The document calls for urgent R&D on exploration methods, understanding rock properties at superhot temperatures, developing stimulation

1. The future of geothermal development in
Iceland
A presentation by Ólafur G. Flóvenz at GGW conference in Reykjavík, 24.11.2016

2. Primary energy consumption in Iceland 1940-2015
0
50
100
150
200
250
300
1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015
PJ
Hydro
Geothermal
Oil
Coal
Peat
Slide from Árni Ragnarsson, ÍSOR

3. UGS – Unconventional Geothermal Systems
− To develop and use EGS technology at present reservoir depths
− To address Superhot Geothermal Systems
− To explore for high temperature systems inside the volcanic zone of Iceland but
outside the presently known high temperature system.

4. Simplified geothermal map of Iceland
© Ólafur G. Flóvenz
The volcanic rift
zone about
32000km2 and
with average
temperature
gradient of about
100 °C/km
Protected High temperature field
Harnessed high temperature field

5. Sketch of a typical
magmatic geothermal system
Downflow cooling
Low permeability rock
Heat source
Permeable fractures
250-350°C reservoir
Steam zone
High permeability zone,
superheated or supercritical fluid

6. Resistivity structure and natural seismicity
Outside the known
H.T. fields
Superhot well into the
magmatic intrusion
An EGS well
Conventional well

7. Example of Superhot Geothermal Systems: IDDP-1 in Krafla
Figure from G.Ó. Friðleifsson af HS OrkaPhoto: Elvar Eiríksson, ÍSOR

8. Some lessons from IDDP-1
− The exploration method used to site the well did not
have enough resolution to detect the magma body at
2 km depth
− The well design, selection of casing material and
cementing methods need to be improved to avoid
short lifetime of the well and its wellhead units.
− Chemical problems related to harsh chemistry of the
steam has to be solved.
− At the top of the magma thin but highly permeable
zone exists, most likely due to effective heat
extraction and subsequent cooling of the rock.
− This observation fits perfectly with the experiment
from extracting heat from the molten lava on the
Vestmann Islands in the 1970ees.
400°C100°C
0 m
60 m
From the ÍSOR database

9. IDDP-2
Photo: Tobias B. Weisenberger, ÍSOR Figure from Egill Árni Guðnason, ÍSOR
Induced seismicity around IDDP-2

10. Beautiful landscape to be protected
Photo from Ragna Karlsdóttir, ÍSOR

11. Geological maps

12. International co-operation
Geothermal plant in Indonesia Hot springs in New_Zealand
Photo: Ólafur G. Flóvenz

13. Urgent future R&D topics:
− Development of exploration methods to estimate distribution of temperature
and permeable fractures in the deeper part of geothermal reservoir in volcanic
environment.
− Development of methods to estimate the mechanical properties of rock in
superhot geothermal systems.
− Find the best methods to exploit and to stimulate superhot geothermal
systems.
− R&D to introduce and test new concepts in design of boreholes that sustain
superhot geothermal fluids. This includes studies of casing material and
wellhead units, improved cementing methods, flexible casing couplings etc.
− R&D to solve chemical problems related to use of superhot fluid with harsh
chemistry.

14. Thank you