| Title | Tubing Impossible: Rig-less Casing Repair in a Geothermal Well with Coiled Tubing |
|---|---|
| Authors | Edgina Kemala, Toby Ryan, Ben Drew, Sam Payne |
| Year | 2026 |
| Conference | World Geothermal Congress |
| Keywords | |
| Abstract | Maintaining casing integrity is crucial for the long-term reliability and safety of geothermal monitoring wells. This paper presents a successful rig-less intervention using high-capacity coiled tubing (HCCTU) technology to clean out and restore a compromised geothermal well. Conducted in mid-2025, the operation achieved two primary objectives: removal of wellbore obstructions at approximately 219 m and 731 m measured depth (MD) and, most importantly, the restoration of casing integrity by installing and cementing a 6-5/8in casing string from surface to 461 m MD. This intervention marks the first application of HCCTU on a geothermal well of this configuration in New Zealand, demonstrating a viable alternative to conventional rig-based workovers. The paper provides an overview of the engineering design, including the selection of tools and materials, and the operational execution, detailing the step-by-step process of the intervention. It also discusses technical challenges such as tool wear, thermal management, and real-time diagnostics. The methodology offers a scalable, low-impact approach for geothermal interventions requiring minimized surface footprint and improved operational efficiency. This paper aims to demonstrate the viability of rig-less casing repairs of geothermal wells, and offer insight into future applications of HCCTU in the geothermal industry. |