Mitsui E & S: Establishes riser bonding tech for deep water: Seabed at depths of 4000 to 6000m
Mitsui E & S Holdings / Mitsui E & S Shipbuilding / First Heat Treatment Industry
First heat treatment industry:
the only manufacturer in Japan that manufactures drill pipes (dedicated for drilling oil, gas, geothermal power, etc.).
We are pleased to announce that three companies have started joint development to establish deep water riser joining technology.
Japan’s exclusive economic zone: the bottom of the EEZ
At the bottom of Japan’s exclusive economic zone (EEZ)
Rare earth,
Surface layer methane hydrate,
Sand layer methane hydrate,
Submarine hydrothermal deposits,
Cobalt rich crust
Etc. exist.
Future development is expected as a purely domestic seabed resource.
Rare earth mud seabed:
Among them, rare earth mud is on the seabed at a depth of 4000 to 6000m.
The technology for oil and natural gas can only reach a maximum depth of 3000m.
New riser tube developed:
In particular, the technology of riser pipes (from the ship to the sea floor) is the biggest challenge in deepwater deep sea oil and natural gas development.
Conventional riser pipe: flange structure
The joining method employs a “screw-welded flange welded to the steel pipe end”.
Therefore, the total weight of the riser pipe becomes very heavy at deep water.
In other words, it is very difficult to suspend the riser tube from the ship.
High strength riser tube: need
In recent years, the development of high-strength riser tubes that can reduce the plate thickness for deep water has been underway.
However, flange-bonded riser tubes cause a reduction in the toughness of circumferential welds.
We need welding performance to prevent this.
This riser tube: ‘Fine-fit joint’
On the other hand, Mitsui E & S and Daiichi Heat Treatment Industry have developed ‘Flame-fitting joining’ as a new riser tube joining technology.
What is ‘Shrink Fit Joining’:
A short steel pipe (connecting pipe) with an inner diameter smaller than the outer diameter of the riser pipe is heated to expand.
And a technique to insert the riser pipe from both ends of the connecting pipe, and then cool and join it.
If shrink fitting is used as the riser tube joining method,
The connection pipe is lighter than the flange structure
Connection pipe length can be easily changed to the optimum size at each connection point.
Lighter joints than flange joints
Furthermore, since the riser pipe itself does not have a circumferential weld, welding performance and fatigue performance are not required.
In other words, steel pipes with higher strength than standard riser pipes (API 5L standard) can be used, making it easy to reduce the weight.
In this way, shrink-fitting can significantly reduce the weight of the riser tube compared to conventional methods.
This technology is a technology that can greatly extend the working water depth to 6000m.
‘Shrink-fitting joining’: Confirmed effectiveness
Currently, we have conducted a tensile test of a small-scale specimen that has been shrink-fit.
As a result, we were able to confirm the effectiveness of shrink fitting.
In addition, we are currently making preparations to conduct a strength experiment at the actual size of a riser pipe with a depth of 6000m.
Mitsui E & S:
Has riser pipe behavior simulation technology, and has a wide track record of manufacturing offshore structures.
First heat treatment industry:
We contribute to the world with high quality in the production of drilling parts for offshore oil and natural gas.
News Release Mitsui E & S Group