Coiled Tubing Work at a Geothermal Field in Kenya:
Experience, Lessons and Challenges

The coiled tubing unit is applied in multiple operations that include work over, well stimulation and drilling. Work over operations involve sand washing, well cleanout, drilling and milling, gas lifting and induced flowing, fishing, cement squeezing, drainage, cement plug drilling, wax removal and plugging removal. In terms of stimulation it is used in fixed point fracturing, separate layer fracturing, uniform acid distribution and dragging acidification while in drilling it is applied in slim hole drilling, under-balanced drilling, old well deepening and sidetracking of horizontal wells. In geothermal wells the coiled tubing unit is mainly used for well intervention services such as airlifting, scale removal and remedial cementing. The equipment consists of power unit, compressor unit, well control equipment, coiled tubing and injector. This paper highlights the experience, lessons and challenges while performing coiled tubing work in a geothermal field in Kenya. The coiled tubing team working to understand, service and operate every part of the coil tubing unit achieved a major milestone by successfully initiating discharge on two wells; MW08 and MW4A in October and November, 2020 respectively in the Menengai geothermal field. In both wells a dummy run was first performed to determine clear well depth, water rest point and produce P-T profile before running in coiled tubing. The tubing was run in and stationed below the water rest point and discharge initiated. A locally fabricated wash tool was used as the lead tool on the coiled tubing while running in hole.

Keywords: Coiled tubing, work over, well stimulation, geothermal, air lifting