Mission accomplished! two provinces now united by a directed crossing
On Friday, June 2, the team notched up a major achievement as it completed the insertion maneuver for the directed crossing of the Colorado River. This is one of the most important and complex milestones notched up as part of the construction project to lay the President Néstor Kirchner Gas Pipeline (GPNK).
After 50 days of work, the team finally finished laying 1,200 meters of 36" pipes connecting the provinces of Rio Negro and La Pampa, in Argentina. The final maneuvers, which lasted some 11 hours, enabled the pipeline to be connected beneath the Colorado River itself, without at any point affecting the water flow that is so crucial for the entire region.
The first stage involved digging a 12 ¼" pilot tunnel. Mariana Zalazar, who was running point on this maneuver, explains that, “For its execution, we set up a magnetic field on the surface to increase the guidance precision of a probe located near the drill bit. This probe provides information to a software about magnetic north and inclination which enables us to know exactly where the bit is going during drilling."
Then, three broadening stages were carried out at 26", 36" and 48" so that the 36" pipe could be inserted within a 4" fiberoptics sleeve to make it easier to communicate with and operate the gas pipeline. Some 3,000 m3 of bentonite mud was used to swill out the drilled soil to the surface, stabilize the tunnel and provide the pipe with flotation and lubrication during the insertion process.
This is the longest 36” river crossing in the country, and, thanks to the use of horizontal directed drilling (HDD), the maneuver was successfully completed in record time.
For the insertion maneuver, eight pipelayers and three excavators were used to position and guide the pipe column. Furthermore, in order to lay the 36" pipe properly, some 600 m3 of water had to be pumped through it at 2,000 liters/minute to float it through the bentonite mud fluids filling the perforation. This meant installing an Australian-type tank close by, managed by a team from the Cleaning and Drying phase of the Techint-SACDE Joint Venture, to coordinate the pipeline filling operation as precisely as possible with the drilling team.
"It was a huge challenge to get this job done in such a short time and prepare it at such short notice. We were the back-up plan and we ended up going out into the field ourselves to make the crossing happen, as the local drilling subcontractor they’d hired couldn’t use their own equipment as it had been damaged in a previous job. This all involved enormous efforts and support from the Machine Park (TEPAM) who were always on hand to help us to handle equipment, materials and spare parts," explained Alejandro Aguirre, Head of Corporate Innovation and an operational specialist in HDD crossings.
The work group involved some 60 people of six different nationalities hailing from many different areas: Quality, Safety and Occupational Health and Environment, (QHSE), Logistics and Lifting, Blacksmithing, equipment operators, local helpers, drivers, workshop and dredging, and two groups of subcontractors, as well as electrical and mechanical technicians from TEPAM, among others.
"At a personal level, this was an incredibly intense experience that involved a lot of effort, but it was also really satisfying. HDD field works are continuous operations, often involving double shifts, where you need to be absolutely sure that nothing is missing so that work doesn’t have to stop, which could jeopardize the success and integrity of the drilling operation. The days in the field were really long, so that we could ensure that everything went well, but it was truly worth it—and I was very lucky to have my family come visit so they could see for themselves with pride what we are achieving," concluded Alejandro.