Challenges and Background: Pipeline welding in offshore or riverbed locations is arduous as they are mostly in hard-to-access locations. Due to extreme and risky conditions, there are many challenges pertaining to health, safety, and environmental that can be overcome by using sophisticated automation and robotics technologies. Automated welding robots with autonomous capabilities are now increasingly being preferred to mechanized or semi-automatic welding operations as they offer increased efficiency, consistency, and quality. However, most of these offshore locations are quite far from reliable energy sources and require batteries that can last much longer than usual.
L&T Technology Services (LTTS) has over 80 years of experience in the oil and gas sector. Having worked on 200+ platforms and 4,500+ kms of pipeline projects, LTTS understands the challenges and opportunities of this sector. LTTS’ unique differentiator is their ability to cross innovate by converging the best technologies from several industries into a single product, and a prime example of this is the autonomous welding robot for offshore pipelines.
Client’s Requirements: The industry’s largest manufacturer of specialized pipelines was looking for long-lasting batteries for critical operations. A leak or rupture in a pipe disrupts the pipeline operations, with a consequent loss for the company. Moreover, many of the pipes that required timely welding were too narrow for humans to enter. The client specified these requirements:
- Develop a battery-operated robot welding machine which can fit inside a pipe of just 1” thickness
- Design a battery for 2-pass welding for pipes with dimensions ranging from 8” (16 mins duration)-20” (42 mins duration)
- Products to be thermally compliant and battery to be IP63 compliant
End-to-end Solution Deployed: Using their in-house expertise, LTTS developed a battery-operated autonomous welding robot system, which can intelligently weld depending on the varying thickness of the pipes. LTTS delivered the automated capability for internal welding of pipes having a diameter as small as 8” outer with battery chemistry to provide constant power for 90 percent of the discharge time.
Power source design: Designed to fit into a 6” space. It had a 5.5 KW power rating to power a welding unit, with a DC source to deliver 170A at 100 percent duty cycle. The challenge was to fit advanced power electronics into an 8” pipeline.
Heat dissipation: To dissipate the heat generated during the welding process, a water-cooled heat sink was designed to maintain temperatures (worked at 95 percent efficiency).
Robotic technology: This enhanced operator safety and efficiency offered a digital interface with a joystick for robot control and was compatible with the existing OEM system for monitoring internal pipe welding.
Business Benefits: The customer was satisfied with the end-to-end solution provided by LTTS, which increased welding efficiency, reduced downtime, and enhanced operational safety. The correct battery chemistry was identified to support welding at full load (16 and 4 minutes with 42 mins of performance per charge). Further, the battery chemistry was analyzed and validated to provide constant power for 90 percent of the discharge time.
Keywords: LTTS, Offshore Pipelines, Welding, Robotics, ARC Advisory Group.