PERSPECTIVES
Djiboutian Development Office of Geothermal Energy
Presented by
ROKIYA HOUSSEIN HASSAN
19 Septembre 2017 GEOTHERMAL SITE IN THE REPUBLIC OF DJIBOUTI
Geothermal sites 1. Lake Abhe 12. Nord Ghoubbet (Afaî-Bolli Daar) 2. Sakalol 13. NE Ghoubet (Assa Foo) 3. Arta 14. Modayto (N Gaggade) 4. Asal Fialé 15. Obock 5. Asal gale-le-koma 16. Okililaeou (SE Gaggade) 6. Balho 17. PK 20-Ambado 7. Daggadé (W hanlé) 18. Roueli 8. Dimbir-Didir (W 19. Sakalol Gaggade) 9. Garabayyis ( E Hanlé) 20. Tadjoura 10. Karapti-san 21. Agna-Galafi (NW Hanlé) 11. Manda Inakir 22. Sud Est Ghoubbet TIME SCHEDULE FOR SURFACE STUDY
YEAR 2018 2019 2020 2021 2022 ACTIVITY
Surface Study : Arta, NE-Ghoubbet and SE-Ghoubbet
Complementary surface study : North Ghoubet and North-West Assal Surface Study : Dimbir-dirdir, Daggadé, Okililaeou and Agna Complementary surface study : Obock Surface Study Site : Tadjourah and Roueli Complementary surface study : Sakalol and Alol Surface Study : Karapti-San and Balho Surface Study : Manda-Inakir and Modayto NORTH-GHOUBBET GEOTHERMAL SITE
Previous study
Due to previous study done late in the 1987, The North-Ghoubhet geothermal field represent one of a high enthalpy field.
In 2010, high level exploratory study combining geophysical measurements, geochemistry shown that there is a conductive surface in the upper layer.
The chemistry of the condensate gas and the spring demonstrates low salinity of the fluid compared to the Asal field and the chemical mark of the fluid was bicarbonate.
COMPLEMENTARY SURFAC E STUDY FOR NORTH-GHOUBBET
• Extension of study area for geophysics • Sampling all fumaroles, hot springs and wells • Identify the alterations zones OBOCK GEOTHERMAL SITE
Previous study
This region of Obock presents a frequent tectonic activity resulting in the presence of the three faults systems on all the sedimentary formations and that of the volcanic formations. Older Exploration study presented a geophysical measurements, geochemistry and geological study and it was carried out in 2013. The results shown that the MT method reveals a conductive anomaly from 1500m deep to 3000m deep and the reservoir temperature was estimated between 170-210°C. COMPLEMENTARY SURFAC E STUDY FOR OBOCK
• Sampling all fumaroles, hot springs and wells • Identify the alterations zones • Off-shore study • Bathymetry SAKALOL/ALOL GEOTHERMAL SITE
Previous study
This study area is located in the northwest extension of the Asal rift segment. During this surface study, 36 MT surveys, 24 TDEM surveys and 65 stations for gravimetric were carried out and also seventeen hot spring and some drill holes and well were sampled and analysed. According to the electromagnetic data, the subsoil is very conductive in its superficial part and it would be a medium-enthalpy reservoir without heat source at Sakalol. The MT data indicates a deep conductor to Alol. NORTH-WEST ASSAL GEOTHERMAL SITE
Previous study
Since fifty years, several study was done in the Assal region.
Three potential reservoirs have been suggested within the Assal rift zone (between Lake Assal and the ocean); North-West Assal, Assal-Fiale and Gale Le Koma.
Wells have been drilled in Fiale and Gale Le Koma that confirm the existence of high temperature at depth in these parts of the area. To date, the only available information on North- West Assal are the available resistivity models (Sakindi, 2015) and the existence of fumaroles close to Lake Assal.
Magma bodies may be found at greater depth than 5-6 km, or below the brittle/ductile boundaries. In that case, the ductile nature of the rock may prevent the escape of magmatic fluids from greater depth.
Complementary surface study for Sakalol and North-West Assal
In this area, the complementary surface study must be undertake : geology, geochemistry and geophysics (off shore study).
Geological study
• Detailed mapping of the area • Collect of the logs of wells
Geochemical study
• Sampling of hot springs , fumaroles and drill holes and well • Analyses of major ions and isotopes
Geophysical study
• Extension of study area SURFACE STUDY SITE
In this area, the complete surface study must be undertake : geology, geochemistry and geophysics because there is not surface study that has been done until now.
Center of the country : Arta, NE-Ghoubbet, SE-Ghoubbet and Assal-West Black circle
South of the country : Dimbir-dirdir, Daggadé, Okililaeou and Agna Blue circle
North of the country : Tadjourah and Roueli Red circle
North-West of the country : karapti-San and Balho Orange circle
TIME SCHEDULE FOR DRILLING PROGRAM
YEAR 2018-2019 2019-2020 2020-2021 2021-2022 ACTIVITY Drilling and tests : Asal-Fiale and Gale le Coma Well drilling program of geothermal gradient and slim hole : PK20-Ambado Drilling and tests : Arta, Nord-Ghoubbet, Assal-Ouest and Garrabayis Drilling and tests : Dimbir-dirdir, Daggadé, Okililaeou and Agna Drilling and tests : Obock, Tadjourah and Balho THANK YOU FOR YOUR ATTENTION