Geothermal Exploration of Olkaria and Menengai fields

Sustainable Development Goals Short Course IV on Exploration and Development of Geothermal Resources

Victor Otieno

Geologist

Kenya Electricity Generating Company PLC

Geothermal Exploration of Olkaria and Menengai fields

24th November, 2019

SDG Short Course IV on Exploration and Development of Geothermal ResourcesOrganized by UNU-GTP and KenGen | Lake Bogoria and Lake Naivasha | Nov 14-4 Dec, 2019

Outline

• General Introduction.

• Olkaria geothermal field.

• Menengai geothermal field.

• Conclusion


General introduction


General introduction cont’d


Olkaria Geothermal Field

• Field size- 240 Km2.

• Geothermal License Area-204 Km2.

• Located within Olkaria Volcanic Complex.

• Geothermal potential- 1200 MWe.

• Exploration for geothermal resources- 1952

• Divided into 7 sectors/sub-fields.

• Aggregate installed capacity-865 MWe.

• KenGen PLC & OrPower 4 Inc.


Olkaria Geothermal Field cont’d


Exploration history

• In 1952-Studies carried out by a consortium of companies-EAPL., PSC., AEIE., Babock & Wilcox Ltd.

• In 1956- X1 and X2 were drilled (950 m and 1200 m).

• 1966- a resistivity survey done.

• 1971- UNDP/GoK- geothermal exploration (Olkaria- Lake Bogoria).

• Geological mapping, hydrogeological surveys, gravity studies & infra-red imagery surveys.


Exploration history cont’d

• Recommended deep drilling of 4 deep wells- 2200 m.

• In 1973- OW-01 drilled- 102 0C at 1 km depth.

• In 1974- OW-02 drilled and struck steam- 1350 m.

• By 1976- 6 exploratory wells had been drilled.

• Feasibility study by SWESCO and VRKIR consulting group.

• Recommended development of 2x15 MWe power plant.

• After the feasibility study- UNDP pulled out of the project.

• Active drilling for a 30 MWe power plant continued- GENZL.

• Additional wells drift thereafter.

• In1981- 15 MWe of Olkaria 1.

• > 300 wells drilled to present.

• Continuous exploration & development- current status of the field.


Olkaria Geothermal Field- Geology

• Surface geology- pyroclasts, pumice, comendites.


OGF- Structural setting


OGF- Lithological cross-sections


OGF Stratigraphic model


OGF Conceptual model


Menengai Geothermal Field

• Exploration by KenGen- 2004.

• Detailed surface studies by GDC- 2011.

• Developed by GDC.

• > 54 wells have been drilled.

• Has realised a potential of about 170 MWe.

• 105 MWe to be developed by IPPs.

Orpower 22 Ltd.

QEAPL.

Sosian Menengai geothermal power Ltd.


Menengai Geothermal Field


Menengai Wells


MGF- Components

Menengai Caldera.

Ol’rongai TVA.

Solai graben.


MGF- Volcanic phases

•Pre-caldera.

•Syn-caldera.

•Post-caldera.


MGF- Geology

• Pyroclastics.

• Ignimbrites.

• Trachytes.

• Basalts.


MGF- Structural setting


MGF- Lithological cross-sections


MGF stratigraphic model


MGF Conceptual Model


Conclusion

• Capacity building key.

• Improvement in technology- current to status of the fields.


THANK YOU


INFORMATION

Name of course: SDG Short Course IV on Exploration and Development of Geothermal Resources

Location: Lake Bogoria and Lake Naivasha, Kenya

Timing: November 14-December 4, 2019

Organized by: United Nations University Geothermal Training Programme (UNU-GTP) and Kenya Electricity Generating Company PLC (KenGen)

Financed by: UNU-GTP and KenGen

Presentation author(s): Victor Otieno ([email protected])

Kenya Electricity Generating Company Company PLC

P.O Box 785-20117, Naivasha

www.kengen.co.ke

Documents

Geothermal Exploration of Olkaria and Menengai fields