World's OFFSHORE VESSELS

[pakarang]

Siem Pearl is really a handsome vessel... love the way the red hull paint is done! Unusual, yet interesting.

[Sterkoder]

Seismic vessel "CGG Føhn" in Kristiansund this afternoon


Seismic vessel "Geo Baltic" inside small offshore vessel "Guard Merlin"


"Guard Merlin" a bit closer


Guard vessel "Thor Guardian" outside "Victory-G"

[pakarang]

Really envious of all ship visits to your city S!

[pilotdane]

Me too. I don't think I would get much work done. I would spend half the day with my nose pressed against the window and the other half the time I would be running down to the waterfront to get a better picture.

[ombugge]

The Guard Marlin and Thor Guardian are what is known as Guard Vessels, or more popularly "Chaser Boats". The seismic vessel/mother ship is usually towing 6 "Guns", which create the sound waves and a number of Streamers behind her. The Streamers are normally 4 - 10 in number and 6-8 km. long, (but can be up to 12 Km. long and up to 22 in number on the largest Seismic Vessel in existence) contains a number of hydrophones to pick up reflected sound waves from the formation below the seabed.

The Chasers are there to keep other ships, especially fishing vessels, away from the towed array and clear the path of any debris, or fixed fishing gear that may get entangled in the Streamers.

The Victory-G looks like a Support Vessel, which is used to bring fuel and supplies to the mother ship at sea to avoid interrupting the operation, but may also function as Chaser when needed.

I don't have any detailed pics from any big and complicated Seismic Vessels, but a lot from a small and old one, which I will dig out and post here at some time.

[pakarang]

Thank you very much for a very good explanation there ombugge! I'm sure many of us learned something new!

Are the hydrophones mounted in the hull or are they towed behind the ship?

[ombugge]

Are the hydrophones mounted in the hull or are they towed behind the ship?

As said above; The Streamers contains a number of hydrophones to pick up reflected sound waves from the formation below the seabed.

Here is a couple of diagrams that shows how it works.
Plan View of a Seismic array being towed:

The 6 Air Guns (Source) is towed just behind the vessel. The Streamers, which can be up to 12 km. long, if single streamer is used (For 2D acquisition)
Here 6 streamers are towed behind for 3D data acquisition.

Here is the same in Profile:


I have found detailed pics from an old 2D Seismic Vessel, which should make it all much clearer. Reverting.

[pakarang]

OK, thank you very much... now it is much clearer! How interesting!

[ombugge]

Me too. I don't think I would get much work done. I would spend half the day with my nose pressed against the window and the other half the time I would be running down to the waterfront to get a better picture.

It could be worse, you could live in Singapore, where we have 7-800 ships in port at any given time. But then again, there is no way you could cover them all, every day so you would probably just get more selective.

[Sterkoder]

"Geo Arctic" docked in Kristiansund this afternoon


And this is what it looks like from the stern


I guess this would be the seismic cable

[pakarang]

I guess this would be the seismic cable

E... look: how "pretty" colors is that?

[ombugge]

The Geo Arctic appears to be towing a single and very long Streamer so it is what is known as a 2D Vessel. They shoot the early seismic in a new concession and cover large area to determine where the best prospects are. This is followed by the more sophisticated 3D Vessels who shoot a much tighter grid to pinpoint the best drilling locations.

As Seismic Vessels is the flavour of the week I will post some pics from one of the older such vessels in existence, "KS Explorer", taken early this year while she was in lay-up near Batam, Indonesia.

The KS Explorer is also a 2D Boat, built as a Factory Trawler in Germany in 1967, converted to Seismic Vessel "Skandi Pioneer" in 1981 and further upgraded in 1990. She last carried the name "Odin Explorer", before being sold to the present Singaporean Owner.

She is equipped with two Streamers and four Air Guns, with most of the electronics updated only a few years ago.

Here she is at Kabil Anchorage, Batam:


Looks a little worn but nothing that some sand blasting and paint can't fix:


This is the stern with two "slipways" for deployment/recovery of the Gun Arrays:


Here is a view of the bridge from the bow:


And from inside the bridge:


The Manoeuvre Panel is much as it would have been back in 1967:


As is the Main Engines:


And the CPP Unit:


The Bow Thruster is a new addition from 1990:


The Engine Control Room is much like it was from the origin:

[ombugge]

The Anchor Windlass is also "vintage":


A view along the upper deck, Stbd. side:


And along Port side:


Now to the business of shooting Seismic. This is two of the four Gun Arrays, suspended from a Float and hanging in gantry beam above when not deployed:


A closer look at individual Air Guns in the arrays:



This is one of two Gun Reels, holding the umbilical that goes from the Gun Shack to the Gun Arrays:


It takes a lot of air, compressed to 2000 PSI, to make a proper "BANG" on demand all the time, every time.
Here is one of two diesel driven compressors below deck:


And two electric driven compressors, also below deck:


As a later supplement is another diesel driven compressor on deck:

[ombugge]

Now the "Source" has been covered. But we have to be able to pick up the reflections from the sub-sea soil.
Here is two Streamer Reels, containing 8100 m. of Streamers each:


And one of the Tail Buoys, containing a DGPS receiver, used to pinpoint the position of the "Tail", which enable the navigation system on board to calculate the position of every hydrophone in the Streamer:


Now to the Instrument Room, where all the acquired data is collected and stored.

The Seismic Technicians sits in air conditioned comfort watching and controlling the operation:


As does the Position Surveyors:


And all of this gets processed and stored in this Instrument Rack:


To ensure that the temperature and humidity in the Instrument Room is kept at the right level for the instruments and people, additional Air-conditioning units are installed:


Without good food, nothing works. Here is the Galley:

On the day these pics were taken they had a bit of problem with the plumbing so water was pumped up into a drum for the cook to use.

This is the Mess Room:


It is not all work and no play. This is the Recreation Room:

I don't know who picked the colour scheme.

[pilotdane]

Very interesting pictures. I had to search online to find out how a seismic air gun operated.

[pakarang]

Thank you very much for the tour of KS Explorer!

[Sterkoder]

Heavy rain and not the best light conditions in Kristiansund this afternoon, as you will see from the quality of my pictures...., not too sharp

"Olympic Zeus" leaving Vestbase to sail into the harbour


Vestbase with a huge rainshower behind


"Olympic Zeus" in harbour


An offshore vessel can also show off her 'J-O View'


At Storkaia was "Normand Ferking" and "Far Serenade" moored side by side


And finally, Vestbase seen from the island Frei south of Kristiansund (Infact, Frei became a part of Kristiansund 1. January 2008).
A part of Frei can be seen in the lower right corner. Vestbase with all the moored vessels is obviously in the middle, and the city mountain Kvernberget is clearly visible. Kvernberget Airport can be seen just above and to the right of Vestbase, and if you use a magnifier, you can see the white control tower close to the right edge of the picture.

[pakarang]

Great images once again from the oily city of KSU!

I must say, the first one, she's got a big crane!

[Sterkoder]

Great images once again from the oily city of KSU!

I must say, the first one, she's got a big crane!

Yes, thank you..., and that "Olympic Zeus" is yardnr. 280 from Ulstein Ship Yard, delivered in March 2009.
That crane's capacity is 250 tons and the vessel's engines deliver a total of 26.149 Bhp.

[Fjordtroll]

Picture was taken Tuesday 22.09.09

P/F Supply Service from the Færøyene which owns
this boat. the boat she was baptized in the Færøyene 28 June 2009.
So she is totally new!
Her name is "Eldborg"