When Weld Repair Isn’t the Finish Line After a weld repair, a wellhead bore might look “fixed.” But in reality… it’s just the beginning. Because once material is added, everything still has to come back to spec: Diameter Surface finish Chamfers Alignment And when the wellhead is welded into place and can’t be removed, sending it to a machine shop isn’t an option. That’s where on-site bore repair and portable line boring come in. The Challenge: Machine It In Place… and Get It Right This project required machining a wellhead bore that had been built up through weld repair. Key constraints included: The wellhead was non-removable Bore needed to be brought from ~16.4″ back to final spec Depth of cut: ~8 inches Surface finish requirement of 125–250 µin Critical 45° bottom chamfer needed to be clean and consistent This wasn’t just cleanup work… This was precision machining inside a confined, fixed assembly. The Solution: Portable Line Boring Setup To restore the bore, our team deployed a portable line boring system configured specifically for this application. Setup & Fixturing Installed a boring bar system aligned to the existing bore geometry Utilized setup spiders and bearing supports for stabilization Built out fixturing to maintain alignment through the full depth Everything had to be dialed in before cutting started… because there’s no margin for error once you begin. The Machining Process With the setup complete, the team moved into machining: Bored the wellhead from ~16.4″ to final diameter range Maintained tight tolerances throughout the bore Achieved required surface finish (125–250 µin) Cleaned up the 45° bottom chamfer using custom tooling Ensured geometry was consistent from top to bottom All completed in place, without removing the wellhead from service. Why On-Site Bore Repair Matters Projects like this highlight the value of portable machining in the field: Eliminates the need to remove large, fixed equipment Reduces downtime significantly Maintains alignment in the equipment’s true operating position Allows for precision results in real-world conditions And most importantly… It turns a weld repair into a fully restored, in-spec component. The Difference Is in the Details Anyone can add material with a weld. Bringing that component back to exact specifications… That’s where skilled machinists make the difference. Because the gap between: “Looks good” And “Is right” …lives in the last few thousandths of an inch. The Bottom Line On-site wellhead bore repair isn’t just about having the right equipment. It’s about having machinists who understand: Alignment Geometry Surface finish And how to execute under real-world constraints Portable machining makes the work possible. Experienced machinists make it successful. Weld buildup prior to machining, showing material added for bore restoration Portable line boring setup machining inside a fixed wellhead assembly Custom tooling used to restore bore geometry and chamfer profile Freshly machined wellhead bore restored to final diameter and surface finish