Repairs in the jungle - part one

It was an urgent repair request that called us out into the middle of the jungle in the middle of August. The humid air was alive with insects and the drone of the river as we disembarked from the boat. Behind us was Barrancabermeja and civilisation. Ahead was almost a mile of steaming Colombian jungle. A jungle filled with puma, poison dart frogs and pit vipers. A jungle through which we would walk to a pipeline repair located underneath the Magdalena River – the very river on which our unloaded supply boat was now sailing away, leaving behind a crackling walkie-talkie as our connection to the rest of the world. Picking up the boxes of supplies and equipment, which included a generator and gallons of fresh water, we began our walk through the jungle.

The Magdalena River has a reputation as being ‘the most dangerous part of the world,’ earned partly from the years of warfare that have engulfed the area and partly from literature and journalists, but walking through the jungle in the August heat, it was easy to picture pitfalls around every bend. In fact, one member of our eight man crew carried a shotgun, in order to ward off vicious prey – animal or otherwise – that might stalk our vulnerable caravan.

The walk was made more precarious by the fact that the ground was such a muddy mire that we had to walk on the pipeline to be sure that we were following the right path. A wrong step off the pipe meant the exhausting task of hauling self and load up out of the sucking mud, which was 3 in. deep in spots, and back up onto the pipe. Not an easy task under the best of circumstances, but when weighted down with over 20 lbs of equipment or supplies, not to mention hip waders or rubber boots, digging out from the mud, retrieving the fallen boxes, and regaining footing on the pipe, took increasing effort.

And just what was it that called us out to such a treacherous spot, at such an unforgiving time of year? The energy company that owned the pipeline had discovered that the 900 psi (62 bar), 12 in. OD petroleum transmission line had substantial wall loss over a 42 in. area, including a bolted flange. This pipeline was instrumental to their service and could not be shut down. A full replacement of the troubled section, scheduled or not, was out of the question.

A river runs over it

Finally, after more than a half-mile slog balancing on the mucky 12 in. pipe, we reached the repair site and quickly set up camp. Since the surrounding area was either mud 3 in. deep or underwater, we first had to use sandbags to create a temporary dam around the section of pipe and flange in need of repair. Even with the sandbags in place, the Magdalena kept weeping into the freshly dug trench, seeping around the edges, as if to remind us to hurry.

Once we had identified the site to be repaired, we began surface preparation. First, we fired up the generator. In order to promote proper adhesion following the standards for surface preparation established by NACE 2 or Sa2.5, we used an MBX Bristle Blaster to remove the mud, rust, paint, and any other foreign matter from the surface of the pipe. While cleaning the steel, the MBX Bristle Blaster also creates an anchor profile, which allows the composite-reinforced coating system to properly adhere to the pipe’s substrate. Working quickly so that the freshly profiled pipe and flange were not re-contaminated, we cleaned the steel surfaces with solvent wipes that contain a high percentage of alcohol and no oil.

With the pipe and flange cleaned and prepped, it was time to restore the pipe to its original configuration. Any pits in the steel substrate were filled with NRI’s Syntho-Poxy™ HC. Syntho-Poxy HC is a high-compressive, two-part, load-transferring epoxy compound that cures quickly and is used to reinforce and reconfigure pipes. Using cartridge guns, we applied the Syntho-Poxy HC, filling each pit with the epoxy compound as needed. Combined with the next steps in the composite system, the epoxy would help to transfer the pipe’s load stresses from the damaged pipe wall to the composite system.

Next, the entire repair area was coated with Syntho-SubSea™LV, a solvent-free, two-part, Kevlar® reinforced epoxy. Able to displace water, this two-part epoxy is designed to stop corrosion. It is engineered to cycle and work with the 900 psi (62 bar) pipeline. After mixing the epoxy resin with the curing agent, we applied the 100% solids mixture onto the pipe and flange using trowels and putty knives at a thickness of 30 mm.

Written by Jose Zapata, NRI, USA, and edited by Hannah Priestley-Eaton

Read the article online at: https://www.worldpipelines.com/special-reports/29052015/repairs-in-the-jungle-part-one/