Geothermal drilling services for Kenya Electricity Generating Company (KenGen) form the backbone of steam resource development within the Olkaria geothermal complex located in Olkaria, Naivasha. The operation involves siting, drilling, testing, and completion of production and reinjection wells designed to tap high-enthalpy geothermal reservoirs hosted in fractured volcanic formations. Wells typically target depths between ~1,500 m and 3,500 m where temperatures exceed 250 °C. Rotary drilling rigs equipped with high-temperature mud systems, specialized bits, and blowout preventers are deployed to manage corrosive fluids, high pressures, and unstable formations characteristic of rift-valley geothermal geology.

KenGen’s drilling workflow follows a structured sequence: geological and geophysical interpretation → well pad civil works → conductor and surface casing installation → directional drilling into reservoir zones → discharge testing and well evaluation. During drilling, real-time monitoring of rate of penetration, mud losses, temperature gradients, and pressure signatures is used to identify permeable fractures carrying steam. After drilling, wells undergo discharge testing to determine mass flow rate (t/hr), enthalpy, and non-condensable gas content, which directly informs power plant sizing and steamfield management. Reinjection wells are simultaneously drilled to maintain reservoir pressure and sustainability by returning separated brine back into the geothermal system.

Operationally, geothermal drilling services at Olkaria are continuous development drilling rather than exploration drilling; the objective is field expansion and make-up wells for existing power stations. The activity integrates drilling engineering, reservoir engineering, steamfield pipeline design, and plant operations into a single production ecosystem. Because geothermal wells serve for 25–40 years, emphasis is placed on casing integrity, cementing quality, corrosion mitigation, and scaling control (silica and calcite). The drilling program therefore functions not only as a construction activity but as a long-term energy infrastructure investment supporting Kenya’s baseload renewable electricity generation.