In an environment of ever more difficult oil and gas projects, pipeline technology is becoming increasingly critical to the success of those projects, and the pipelines themselves represent a growing percentage of field development costs. Ex-BP engineer and Senior Project Manager at J P Kenny Graham Freeth says the onshore pipeline construction industry has been an innovation desert for the last 30 years, and has much to learn from the radical advancements made in the offshore pipeline industry over this period.

The challenge of the North Sea was quite significant, and therefore the focus was on developing new technologies to suit the requirements of the offshore market, Mr Freeth told MEES. Because there was no real push to do things bigger and better with onshore pipelines, we just carried on doing things the same way we did 60 or 70 years ago, with some minor changes to improve productivity. But there is now a demand for smarter solutions.

The traditional method still used to build onshore pipelines involves transporting individual 12m lengths of steel pipe by truck and laying them along the side of a trench, welding them together and lifting them in by side booms. But from the start of an onshore pipeline project to its construction and beyond, there is ample scope for applying new technology. This includes better ways of selecting the pipeline route, using stronger pipeline material, transforming the welding process, and improving the operation and maintenance of the pipeline once it is complete, which can significantly extend its operational life.

Tougher Materials, Better Construction Techniques

Making pipelines stronger, to withstand higher pressure and transport bigger volumes of gas, is a key area for innovation. The widely used X70 pipeline can withstand 70,000 pounds per sq in (psi) of pressure. The X100 and X120 pipelines, which can handle up to 100,000 and 120,000 psi of pressure, simply use stronger steel. Pipelines subjected to higher pressure require different kinds of steel, such as carbon fiber and martensitic steel. While there is a slight increase in the cost of manufacturing reinforced steel pipes, Mr Freeth says the extra value from being able to put higher pressure through the pipe easily compensates for this.

Ninety-nine per cent of pipelines are made of steel, and this is considered the solution at least for the medium term. But the opportunity to develop alternatives is illustrated by the facts that steel prices have risen sharply over the last 10 years, from as low as $200/ton in 2002 in Northern Europe to more than $1,200/ton earlier this year, and that major industrial projects require vast amounts of steel piping - 4,000km in the case of Saudi Arabias 1.2mn b/d onshore Khurais field, due on stream in June next year (MEES, 2 June).

Offshore Vs Onshore Pipeline Installation Progress