• Question: What is a problem you have come across in your field and how did you overcome it?

    Asked by Whatlerly_road to Matthew, Neil, Paula, Pete, Philippa on 11 Mar 2015.
    • Photo: Neil Taylor

      Neil Taylor answered on 11 Mar 2015:

      Hi!

      A frequent problem in my industry is managing the temperature of a pipeline. Oil and gas is usually very hot when it comes out the ground (often much hotter than boiling water!), and this means that the pipe that is carrying it can get very hot too, which makes the pipe want to expand.

      The soil that is on the seabed doesn’t let the pipe expand as much as it wants, which puts the pipe into “compression” (it squishes it). You can make the same sort of thing happen by pushing at the ends of a plastic ruler. This can cause problems such as “buckling”, where the pipe suddenly moves sideways! You will see this happen to your ruler if you push hard enough.

      So we know that too hot = potential problems…. But what about too cold? Well, if the pipe is long (let’s say it’s 50 km!) then a lot of heat will be lost to the surrounding seawater , which is cold (4°C is often assumed). If the pipe cools down too much, then waxy substances can form that can block the pipe!

      So we also know that too cold = potential problems…

      The temperature of the oil and gas coming out of areservoir will reduce as more is extracted. This means that during its early life (when the oil/gas is hotter), the pipeline must not be too hot… but during its late life (when the oil/gas is cooler), the pipeline must not be too cold! The question then arises: How can we design a pipeline that can be suitable for both early and late life?!

      This was a problem that my team were faced with. Our solution was to create a “cooling loop”. This is where we designed a part of the pipe to loop around on itself several times, so that heat is lost to the surrounding seawater.

      The clever part is that we designed to system to have the ability to direct the oil/gas around many loops during early life (when it is hotter), and less loops during late life (when it is cooler). By carrying out a lot of work, we were able to create a design that was suitable for the whole of the reservoir life!

      This is a fairly long answer – hope it helped and was easy enough to follow!

    • Photo: Pete Symons

      Pete Symons answered on 11 Mar 2015:

      Hi Whatlerly_road,

      I come quite a lot of different problems in any particular job I am doing a the time, but one of the more interesting problems was when I was working on the Air to Air Refuelling Pods for Cobham.

      http://www.cobham.com/about-cobham/mission-systems/air-to-air-refuelling/products-and-services/hose-and-drogue-systems/wing-air-refuelling-pods.aspx

      The basic principle of Air to Air refuelling is that when a jet needs more fuel (because they only have small fuel tanks, if they are travelling across large areas of water they cant land and so need to refuel in the air) they need to ‘couple’ to a tanking aircraft. To do this the jet has a probe on it which you may have seen in pictures before, its a telescopic rod on the top of the jet.

      The probe has to connect with a long hose wound out by the tanking aircraft with a ‘basket’ basket on the end. The way it connect is through a valve which opens once a successful airtight seal is made between the jet and the tanking aircraft.

      One of the problems we had (during testing) was that the jet probe was having to really hit the basket with a lot of force to create the seal because the pressure inside the fuel system on the tanking aircraft was too great. We had to design a venting system for the fuel still in the tanking aircraft hose when a jet wanted attach but it couldn’t freely vent fuel as that would be bad for the environment as also you could create a pressure difference the other way otherwise the jet might not be able to detach.

      It was a really interesting problem and the venting system we designed worked in the end.

    • Photo: Philippa Jefferis

      Philippa Jefferis answered on 15 Mar 2015:

      My main problem at work is working out how to repair a bridge that was built in the Victorian age. The first problem is understanding how it was built, as we don’t always have very good records of this. Sometimes we are lucky, but most of the time we have to base our assumptions on how we know similar bridges have been built.

      Then we need to understand what the bridge needs to be able to carry in terms of load (weight from traffic, it’s own weight, wind).

      Then by assessing how the bridge is failing by looking at where the cracks are, or whether it has rusted in key parts. From this we start to design solutions to bring the bridge back to being able to carry the right load.

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