Mega-Structure – The World’s Longest Subsea Pipeline

“World’s Longest Subsea Pipeline” is a documentary that explores the construction of the longest subsea pipeline in the world, which connects Norway to Britain. The pipeline is a major project in the gas industry and is considered one of the riskiest construction projects ever attempted.

The pipeline connects Norway’s Ormen Lange gas field, which is 120 kilometers off the coast of Norway, to one of Norway’s largest processing plants at Nyhamna. From there, the processed gas is transported through the Langeland pipeline, which is a staggering 1,200 kilometers long, to the United Kingdom.

The Ormen Lange gas field is one of the largest underwater gas fields in the North Sea, and it contains over 300 billion cubic meters of gas. The gas is locked in an icy tomb 3,000 meters below the sea surface and is considered beyond the reach of man and machine. However, the engineers at Norse Hydro, the Norwegian energy company, saw the potential of the gas field and decided to pursue the project.

The construction of the pipeline took 10 years and cost 10 billion dollars. The engineers faced many challenges in building the pipeline, including drilling nearly 2,000 meters through the seabed to tap the gas field. They used a rip built on the sea floor to achieve this.

The pipeline that brings the gas out of the field and delivers it to the plant has to scale a 300-meter underwater cliff face, and the seafloor terrain is too rough to lay pipe on. The engineers used trenching to overcome this challenge.

To handle the Ormen Lange gas, which is a dangerous mixture of debris and frozen water, they adapted the system to handle it. The processing plant can handle 70 million cubic meters of gas each day.

The engineers used some of the largest industrial ships in the world to tackle different phases of deep-sea construction. These ships were designed to work in harsh North Sea conditions. Underwater remote-operated vehicles or ROVs were used to do the brawny work that humans could not do.

The engineers also faced a challenge in finding a gas well platform that would work in the North Sea’s torturous seas. Existing designs fell short because the weather in the North Sea is too stormy, and the water is too deep.

The engineers came up with a revolutionary solution of dropping a template, which is an underwater gas platform that guides the drills through to the gas field and controls the good flow, onto the seabed clear of the wild North Sea weather. The template combines the function of a surface platform with a seabed drill guide.

The stakes were high for the engineers because they were building a structure that had to operate flawlessly for over 40 years in a harsh saltwater environment. They built it to withstand pressures that would crush a normal submarine. Once the structure was lowered to the sea floor, there was no going back. It was committed to the seabed forever.

The engineers faced another challenge in transporting the 1,000-ton monster to the drop site. They loaded it onto a sea-going barge for transport to the site. The weather was a major factor in determining the success or failure of the mission. The journey to the drop site took four days and was planned to coincide with the summer season, which is the season of the calmest seas in the North Atlantic.

In conclusion, the construction of the world’s longest subsea pipeline was a monumental challenge for engineers. They overcame many obstacles and used some of the most advanced technology to build the pipeline.

The pipeline is a testament to human ingenuity and the quest for energy. It has enabled the UK to import natural gas from Norway, which has reduced their reliance on foreign gas and coal.