A rammer can create the least surface disturbance possible, especially when something is wrong on the job site and quick action is needed
Jake Gautreaux, founder and co-owner of Directional Service South, explained. “For this project, we were commissioned to install several kilometers of 500mm steel gas transmission lines with installation lengths ranging from 150m to 920m and pipe welds coated with ScarGuard. The whole project covered 30 HDD feedthroughs. After one particular 360m long installation, crews noticed a problem with damage to the pipe. It would have to be replaced. »
According to the pipe ramming specialist Rick Melvin from TT Technologies, pipe extraction is an evolution of existing ramming techniques developed over time. “The extraction process is really an extension of several HDD Assist methods we’ve developed over the years using the pneumatic pestle,” he says. “Things we learned from retrieving blocked bores and retrieving drill rods using rammers enabled full scaling pipe extraction become a reality. »
Pulling pipes: it’s about the right balance of forces
Extraction of pipes is part of this process. “Contractors have long used pipe rammers on HDD projects to help install pipes in difficult areas like waterways for a long time,” Melvin explained. “With pullout assist methods, the percussive force of a rod rammer at the back end of a drill string can help prevent hydraulic jamming and ensure smooth installation. Now when things don’t go to plan, a drill pipe breaks or a segment of pipe needs to be removed, we can do those things too, again using the percussion power of the pipe rammer to help remove or recover these products from the ground.”
The percussion force of the rammer causes the pipe to move
Return to Houston: As for the area in question, the whole installation turned out to be trickier than expected. “We installed the crosspiece with no problem, but we weren’t able to hook it up right away,” noted Gautreaux. “We had to turn around and install the next passage, drilling in the other direction. So we were basically sitting on top of the one we just installed. It was only after installing this next section of pipe that we were able to access this first pipe. That’s when they noticed the damage: a large scratch cut through the entire visible length of the pipe and punctured the coating. “A quick decision regarding the future of this section had to be made.”
When the extraction work began, the pipe had already been buried for two months. “Welding the welds is abrasive and creates friction, which makes it extremely difficult to pull the pipe out,” Gautreaux said. Early attempts to use static pulling force to remove the pipe were unsuccessful. “In addition, we wanted to pull the 360 m replacement pipe section at the same time. So we introduced the GRUNDORAM Taurus rammer to complete the extraction setup.
After 10 minutes of pounding and pulling, the pipe finally started to move. All in all, it took two 12-hour days to remove the hose and insert the replacement simultaneously. Crews were able to extract the 360m pipe into two 180m sections. “The hammer worked really well to free the line, allowing the equipment to keep moving,” Gautreaux said. “That’s why we bought the hammer, to have it in our fleet and on the job site. Time is running out when problems arise.