| Title | Implementing Novel One-Trip Solutions for Multi-Lateral Operations from Cased Closed-Loop Geothermal Wellbores |
|---|---|
| Authors | Scott Webber |
| Year | 2026 |
| Conference | World Geothermal Congress |
| Keywords | One-trip sidetracking, Multi-lateral operations, Closed-loop geothermal systems, Combined milling and drilling BHA |
| Abstract | Drilling multi-lateral closed-loop geothermal systems incurs high costs and extended timelines due to repetitive sidetracking trips. In South Germany, for example, eight vertical main wells requiring eleven casing exit windows each would otherwise necessitate 176 dedicated trips (88 for window milling, 88 for directional drilling). To optimize the number of trips, we developed an integrated bottom-hole assembly (BHA) capable of combining whipstock setting, window milling, and extended-reach lateral drilling in a single continuous run. Over an 18-month period, interdisciplinary teams applied data analytics and simulations to analyze historical sidetrack performance metrics and inform iterative BHA refinements. Lean manufacturing and agile design principles enabled rapid prototyping of a whipstock-packer assembly that transitions seamlessly from PDC bit milling to full directional drilling with MWD tools. Once the casing milling is done, the PDC drill bit continues drilling a long lateral wellbore to its total depth. Scheduled for a USA field trial in August 2025 and subsequent deployment in Germany by year-end, this one-trip solution is projected to halve sidetrack trips, cutting 50 percent of related rig time. Anticipated benefits include massive savings per sidetrack operation. By streamlining multi-lateral construction and leveraging advanced sub-surface data integration, this technology sharpens the learning curve and enhances the economic viability of closed-loop geothermal projects worldwide. |