SINTEF and Norway’s LedaFlow Technologies have jointly developed a new computational tool to reduce slugging in oil pipelines.
Called ‘Slug Capturing 2‘, the new tool enables the design of longer pipelines, allowing many more oil fields to be developed as ‘Satellites’.
The Norwegian shelf is covered by a web of pipelines that not only carry oil, but also gas and water – in the same pipeline – through a system called ‘multiphase transport’.
Developed nearly 40 years ago by SINTEF and the Norwegian Institute for Energy Research (IFE), multiphase transport encourages integrated production facilities to be directly installed on the seabed.
It enables unprocessed oil and gas to be transported straight from a field’s production wells to platforms located on neighbouring fields or directly to land.
The only drawback with this system is formation of slugs – long plugs of liquid, separated by large gas bubbles in the pipelines.
Slugging causes massive fluctuations in flow rates and results in vibrations along the pipelines. It can reduce pipeline lifetime and if the plugs are long enough, they can flood the separators in the reception facility.
SINTEF and LedaFlow are hoping to remedy this with their ‘Slug Capturing 2’ module which predicts both the frequency and length of the liquid plugs that form in the pipelines.
It is so accurate that it can increase the multiphase pipeline transport distances – both horizontally along the seabed and vertically upwards from the seabed to host platform decks.
Rystad Energy predicts that as much as 75% of the oil and gas from new Norwegian field developments will be recovered using so-called ‘tiebacks’.
These tiebacks enable production from ‘platform-free’ satellite fields, from which the well stream is transported via multiphase pipelines to existing host facilities with free capacity.
The new simulation tool has also been specifically designed to estimate the mechanical stresses acting on the risers that extend from the seabed up to the platforms.
It helps in optimizing pipeline integrity and preventing leakage without costly overdesigning.
This is particularly important in the case of deep-water production – such as in the Gulf of Mexico – where transport using long risers can create major problems.
Both TOTAL and ConocoPhillips have already started utilizing the most recent R&D version of the LedaFlow-SINTEF simulator to design deep-water risers.
Image and content: LedaFlow Technologies/SINTEF