Increasingly, the energy industry must find ways to co-exist with nearby cities and neighborhoods in densely populated urban areas. Operating companies that are responsible for drill rigs, compressor stations, high-pressure pipelines and other equipment are finding news ways to build, startup and operate massive equipment-intensive facilities in a safe and efficient manner, next to towns, farms and universities.

To achieve these goals, gas-well drillers will build fences around rigs. Compressions stations can be constructed inside noise-suppression facilities. Pipelines are well buried, rights-of-way are marked and surface paths have warnings posted at close intervals along the route. But what happens when an energy complex, originally built away from human dwellings, finds itself in the path of progress?

Such was the case for Repsol-YPF SA, an integrated international oil and gas company that operates in more than 30 countries. Founded in 1922, now with more than 36,000 employees, it is one of 10 major private oil companies in the world and the largest private energy company in Latin America, based on assets.

Among its holdings, Repsol owns and operates a tank farm near Concepcion Del Uruguay, some 320 kilometers north from Buenos Aires. The complex was originally built in an undeveloped region. Yet, over time, the urban sprawl of Concepcion approached and spread around the tank farm. The population grew to 65,000 citizens, who proceeded to build homes, shops and more businesses around the farm, edging closer until the farm became completely surrounded.

Tank 21 is on the move.

The challenge

In 2010, the Concepcion city council decided that the situation posed a health hazard to the encroaching population and that any tank farm should be sited at least 100 meters from the nearest home. Yet, due to the urbanization of the area, Repsol found itself with three petroleum tanks cited some two or three meters of the decreed 100 meters distance. The energy company began to look for a solution to ensure compliance with the Concepcion city regulations.

After deliberation, Repsol focused on three possible strategies. First, it could shut down operations at its tank farm and transfer station. The option was rejected.

Second, the tanks could be placed on new foundations, which would meet the city specifications. To do that, Repsol could cut down and rebuild each tank and each tank’s accompanying foundation.

Or, third, it could lift and move the three existing storage tanks and rebuild each foundation to stay within the new regulations set by the new city council. The third option seemed to be the most cost effective, if it could be accomplished.

During its search for capable contractors, Repsol contacted A.R. Watson Inc. at its office in Bellingham, Washington. The firm was founded by Alan Watson in 1980 as a mechanical engineering and construction business to supply services to the petroleum, petrochemical and gas industries. The company developed and patented the "Watson Air Lift" technology, which uses air bags to lift above-ground storage tanks to allow access for tank-foundation reconstruction, or the installation of a secondary containment, or tank relocation. A.R. Watson has been lifting and relocating above-ground storage tanks for over 27 years and has successfully completed projects throughout New Zealand, Australia, Asia, Europe and the U.S.

The solution

Watson was asked to quote a price for the contract. To properly define the work, Watson traveled to Concepcion Del Uruguay to meet with Repsol. Jointly, the companies decided the best way to solve the issue would be to move each tank in stages, one tank other another. A.R. Watson would oversee the lifting and moving of the tanks and Repsol would look after the foundations.

Once an agreement was reached, A.R. Watson arranged to have the major equipment shipped from Alabama to Concepcion Del Uruguay. The equipment list from A.R. Watson was 12 airbags, 200 meters of air-line hose, one manifold and an air-pressure gauge. Then, A.R. Watson set about gathering the rest of the equipment out of Argentina, such as a Bobcat, forklift, digger, assorted trucks and a quantity of timber to be used to support the tanks aboveground.

Once all the equipment and the A.R. Watson team arrived onsite, the work was begun. The first job was to clear a three-meter space underneath the old concrete foundation to insert four airbags. Each airbag can lift 70 tons. Once the tank is initially lifted off the ground, more airbags are place around the tank in regular intervals to lift the whole weight of the tank.

The airbags lift the tank high enough so that timber supports can be place underneath the tank. When all the timbers supports are in place, the air is release out of the airbag the tank begins to rest on the timber supports. The lifting of the tank is repeated over and over again, until the tank high enough that the workers can begin setting out the supports needed to move the tank out of the way. Then, a new foundation will be built.

Specifically, two rows of timber stacks were built under the support tank, at a height of 1 meter high by 1 meter long by 30 meters wide. A railway track was place on top of each timber stack. Once this structure was ready, A.R. Watson began to lower the tank on top of the “load skates,” which would slide along the railway track. A.R. Watson planned to begin each movement at the start of the day and finish with the tank sitting on steel support at the end of the day. Moment was slow, and was “not how we do things in the States,” but the process worked.

Each tank-lifting movement took a week to complete per tank. Then, when the new foundation was finished, the A.R. Watson team returned to Concepcion Del Uruguay to put the tanks on their new foundation. The tank-moving process was repeated in reverse.

Tank 17 is on its steel frames and the old foundation been demolished.

Final steps

The last stage of lowering the tanks involved using bags of ice. The bags were placed under the tank and on top of the foundation. This final step was meant to support the tanks’ weight while A.R. Watson removed the airbags. When the ice was fully melted, and all the safety checks were completed and approved, the tanks were placed back into service.

At that time, the company discovered that one tank, Number 17, was not placed to sit properly on its new foundation. Tank 17 had to be rotated. A.R. Watson placed 150-millimeter pipes, cut to 1-meter long, at 4 equal locations around the tank. It then lowered the tank on top of the pipes and attached a digger to a chain. The chain was attached to the tank and the chain was pulled in the correct direction to move the tank into the correct position so it could be lowered to be seated perfectly on the foundation.

At the job’s conclusion, Repsol reported satisfaction with the project, both with the project time and cost savings.

Lance Watson is the global operations director of A.R. Watson Inc., based in Auckland, New Zealand.