World's OFFSHORE VESSELS

[ombugge]

This is a continuation of the a post on the Heavy Lift Carrier thread a while ago. This cover the completion of the barrier at Aalfjord, tow to field, installation and present status:

The two barrier halves were anchored in Aalfjord during the winter of 1989 and slipformed to their full height of 120 m. Some of the top walls were installed, but some had to be left out as we would have to bring the barrier into place under the existing bridges to/from Ekofisk Centre:

That "toy boat" floating inside the tub is actually a full size vessel, just to illustrate the dimensions of this barrier.
The little white "boxes" on the right is our "bridge" for the tow (top) and instrument rooms for nav.systems etc. (All are 20' Containers)

Before leaving we did a "Trail Mating" to make sure the two halves would fit together once we set the down on bottom in the field:

They did.

The first half leaving Aalfjord under tow by 9 tugs:

It is mid-summer and near mid-night. Beautyful weather.

For a photo oportunity the 9 tugs for the second half was arranged as if also towing and some were good aerial photoes were taken, but unfortunately I don't find any copies here. (Maybe somebody can find on the net?)
This was the largest fleet of big tugs ever assambled for a single job and the spot market rate in the North Sea has never been higher then when this operation and the Gullfax C tow took plase nearly simultanuously.

Weather en route was perfect, flat calm seas and over 20C. even at night. We had a barbeque on deck:


Due to the draft of abt. 67-68 m. we could not take the direct route to Ekofisk Field. We had to skirt the "shallow" banks to the north by going into British sector and approach Ekofisk Field from the SW.
This is the sight that met us on approach:

The first half had already been positioned and the complex was going at full production. (350,000 Bbls/day C.O.+ Natural Gas for export to Germany)

I don't have any pics of the actual installation process here, but it was the most complex Marine Operation ever performed, in my opinio. Tolarance of relative position between the two half was 7.5 cm., which we acheived

Here is a pic of looking down between the Barrier and the Ekofisk Tank, once in position:


This is a pic taken from the net, showing Ekofisk Centre with its protective barrier in place and completed:

I had long left by that time.

This is what it looks like today:


The production equipment has been removed, but it would be too difficult and expensive to remove the 1 million tonnes Tank and the barrier, which is filled with sand dredged up in the vicinity and probably weigh about the same.
(Weight on tow-out was abt. 230,000 m.t. for each half, of which about 50,000 t. was ballast)

Does anybody have good idea for what to do with such a relic once the rest of the field is removed and only this "Island" is left? (Sorry, no Palm trees)

[Sterkoder]

Standby vessel "Coast Defender" in Kristiansund this afternoon


"Viking Lady"

[pakarang]

That is an awful amount of yellow in a close up...

When I see the whole ship, it doesn't look bad, but in the close up: there is a wee bit too much yellow on that superstructure.

Thanks to ombugge also for that fascinating report on the oil installations: I'm a bit ... how should I say this.... in awe of human engineering and ingenuity.

[Sterkoder]

"Ocean Clever" came in to Vestbase behind "Ernest Shackleton" (ref. the E. Shackleton-thread).


"Ocean Clever" morred with "Island Challenger" behind and "Far Seeker" in front


I know I've uploaded "Far Seeker" before, but couldn't resist more picture of the ship in the clear beautiful light around 7:30 AM this morning



Photos: ©S. Ludvigsen

[Sterkoder]

Took some pictures of some offshore vessels while waiting for the "Balmoral" early Wednesday morning
"Sea Profiler"


"Far Scout"


"Ocean Star"


"Sical Torino"


"Ocean Star", "Far Seeker" and "Far Scout" at Devoldholmen

All: ©S. Ludvigsen

Then I had to go to work, but I explained my boss that I really should have some pictures of "Balmoral" in the beautiful morning light.
He being a shipfreak himself told me to take his car, bring my camera and drive around to take whatever pictures I needed...!
(Nice boss..., don't you think..?).

Pictures in the Cruiseships in Norwegian waters 2009-thread).

[Sterkoder]

"Island Wellserver" undocking from Storkaia

[Sterkoder]

"Ocean Sky" still at Kristiansund Mech. & Shiprepair after a heavy fire in the engine room a couple of months ago


"Ocean Prince" also in for an overhaul


The Ocean-vessels with yardnr. 14 from Sterkoder Shipyard in 1970 on dry dock...., the trawler "Rairo"


"North Traveller"


"Far Sapphire" coming through Markussundet inlet

All pictures: ©S. Ludvigsen

[pakarang]

These reports from KSU are very fascinating... so many ships visit that port, a thrill for anyone even remotely interested in shipping.

[ombugge]

Time for another tutorial from the Offshore industry. This is about Semi-submersible Drilling Rigs, which is the type seen most in Norway. The pictures are taken on different newbuilt Semis so there is no action pics while drilling.

Here is two new rigs doing final preparations before leaving Singapore for their first job. Also two different type of Derricks; the one on the left has a dual Ram Rig Tower, while the one on the right has a conventional derrick:


Here is a closer look at a Semisub rig leaving the building yard for the first time:


A closer look at the same rig and two of the Free Fall life boats:


Here is the Fairlead arrangements for the mooring system. This rig is able to work in 7,500 ft. (2,300 m.) water depth using 8 anchors and in 10,000 ft. WD using Dynamic Positioning System to maintain position:


A view of the Bridge, from where the DP system is controlled while on a drilling location and from where the rig is manoeuvered when under way under own power. Rigs like this usually has 8 thrusters with up to 30-40,000 Horsepower propulsion. The Power Plant supply up to 40-50 mWe electricity to the Thrusters and Drilling equipment:


This is the Driller's Shack, from where all drilling operations are controlled. The Driller, Assistant Driller and Derrickman sit in Cyber Chairs with all functions built into the armrests and flat screens in front of them with all necessary data to control the operation:


Nobody actually need to be out on the Drillfloor, so the cuts you see on News Channels of people pushing pipes and swinging large thongs are from old fashion rigs.

This is what replaces the Roughnecks on the drillfloor, an "Iron Roughneck":


This is the actual drilling machine, known as a "Top Drive", which turns the drill string and drill bit in the well. Able to reach depth of 30-35,000 ft. (9-10,500 m.):


This is the Blow-out Preventer, also known as the Sub-sea Stack. It goes down on the seabed and connects to the wellhead, all 230 t. of it. Capable of closing the well bore and control up to 20,000 PSI pressure:

[ombugge]

Marine Risers stowed vertically on the rig. These goes from the BOP Stack on the bottom to the Drillfloor. The drill string runs inside and the Drill Mud, which is pumped down though the drill pipes to lubricate and cool the drill bit on bottom of the well, is returned to surface by the riser:


The heart of a drilling rig is the Mud Pumps which is used to pump drilling fluid down the well. Here is one of three such pumps on the rig:


This is just a brief description of a Drilling Rig and some of the equipment it carries to be able to perform drilling operations in deep water and to great depths below the seabed. Most of these pics are from Development Drill 1 & 2, which is now operating in the Gulf of Mexico.

[pakarang]

Very impressive tutorial... also, what impresses me quite a bit is the technology involved and how we (read the humans) have become so intelligent that we have figured all these things out, and even to the point of replacing the manual manpower down on the drill deck. We are far ahead of the inventions of the wheel, when looking at these images. It's quite astounding.

[pilotdane]

Do they filter and re-use the drill mud on the platform or is it stored and sent ashore?

I remember watching several Discovery Channel programs that talked about drilling mud. I did not know it was so technical. Special muds are used for drilling through different rock and at different depths. Apparently the mud can make or break the drilling operation.

[ombugge]

Do they filter and re-use the drill mud on the platform or is it stored and sent ashore?

I remember watching several Discovery Channel programs that talked about drilling mud. I did not know it was so technical. Special muds are used for drilling through different rock and at different depths. Apparently the mud can make or break the drilling operation.

Yes the Drill Mud is VERY important to the success of the drilling operation and Very technical. Aside from what I mentioned in the above post, the mud also serve to control the pressure in the well. Simply speaking the hydraulic pressure of the mud column from the bottom of the well to surface balance out the formation pressure at that depth. I.e too light mud you may get a blow out, to heavy you may "break" the rock and loos mud to the formation, which may again lead to a blow out as the mud column gets shorter.
That's why the BOP is so important.

The mud also have to have a certain viscosity because it also serves to bring the cuttings to surface.

And yes, they do treat the mud on board, but in some locations the cuttings has to be brought ashore as they may contain oil residue, either from the formation, or from using oil based mud, as opposed to water based mud.

Here is the first step in the process, the Shale Shakers, which separate the drill cuttings from the drill mud on return:


Samples of the cuttings are taken to check for oil residue. This tedious job is done by a "Sample Catcher" and analysed by an on board Geologist, or sent ashore for even more analysis.

Next step is through the de-gasser, de-sander and de-silter to remove smaller particles that doesn't belong in the mud, before being returned to the Mud Pits and stored ready for the next trip down the well bore. This also involve mud centrifuges on most rigs today.

This is a de-silter;

(Sorry, I couldn't find a good pics of the rest of the mud treatment system on the two rigs these pics were taken from)

Another operation I didn't mention is cementing, which is done to seal the formation where you don't want formation fluid to enter the well, hold the casings in place and to plug and abandon dry wells etc.
This is done by pumping liquid cement down the well using a Cement Pump.
Here is a sample of such a pump:


Third party personnel are engaged by the Oil Companies to handle the mud and cementing operations.

When time permit I'll make up a post about Jack Up Rigs as well.

[Sterkoder]

"Olympic Princess" in town this afternoon. This is a new ship in my archive....

[Fjordtroll]

PSV M/S "Skandi Stolmen"

[Fjordtroll]

M/S "Oms Quest" In Sandnessjoen

[ombugge]

I said some three weeks ago that I would follow up with some pics and tutorial from Jack-up Drilling Rigs when time permits.
Well, here it is. These pics are mostly from newbuilt rigs from Keppel FELS and PML Yards in Singapore, taken a few years ago.

First an over view. This is J/U Deep Driller 1 on location off Cherrypondi, India:


J/U Deep Driller 2 at Keppel FELS for final outfitting:


Drill Floor skidded partly outboard using the Cantilever Beams:

Max. distance the Drill Floor (Rotary Table) can be moved aft of the transom is 70 ft. ( 21 m.) but the rig behind restricted this here. (10 rigs under construction simultaneously)

The Drilling Derrick seen from top of Accommodation Block:


The Cantilever deck and Drill Floor:


Main Deck w/two Cement Pumps seen under the Cantilever deck:


Main Deck with Pipe Rack:


Accommodation Block seen from Wharf (120 pers.) Two 60-pers. Life Boats on either side:


Crane and legs:

There are 2 x 70 t. SWL Cranes, one on either side and 1 x 50 t. SWL on Port side aft. + a small Pipe Handling Crane on the Cantilever.
The legs are 486 ft. (148 m.) long. The Rigs is able to work in 350 ft. (105 m.) water depth.

The Jacking System is "Rack and Pinion" -type, using 12 Electric Motors and gears to drive 12 Pinions per leg. The Jacking System is able to elevate the hull at 1.5 ft/min. (46 Cm./min.) with a total weight of 21,000 m.t. and hold a max. of 31,000 m.t. weight in extreme conditions. (Pre-load):

[ombugge]

This is the Jacking Control Panel, from where the Jacking System is operated:


Ladder down to "Texas Deck" and Conductor Guide at the Transom:


The main difference between a Floating Rig and a Jack-up Rig when it comes to the drilling operation is that on J/U rigs the BOP sits on surface, on top of the Conductor Pipe that is driven (or drilled and cemented) into the top formation. The BOP thus become much more manageable and smaller:


The Control Unit for the BOP is also much simpler:

Here placed on the Cantilever Beam at one side so it follows the drill floor in and out rather then to have to add and remove Chicksans, or have very long hoses, to reach the furthest drilling position.

Finally, a few pics from the Living Quarters for the crew, which is still fairly basic, but has improved drastically from the earlier rigs.
Here is a typical 2-men room:


Mess Room:

Note the pics of a Cruise Ship on the wall. This rig belonged to AWILCO, who also own(ed?) Royal Caribbean Cruise Line, I believe. (The rig now belong to CNOOC, China)

Galley:


Coffee Shop:


Radio Room:


Senior Change Room:


I have hundreds of detailed pics from Rigs, but I thing this may exhaust the interest in this type of things for most CV Members.

[ombugge]

OK, one more. This may grab some interest and put things in perspetective.
A BMC-375 Jack-up almost at the top of its legs during Jacking test:

The test is done alongside the wharf at the yard in approx. 9 m. Water Depth.
(Picture taken from Sembcorp Marine web site)

I can assure you that the view is spectacular when you get up 350 ft. (106 m.) above sea level, (measured from underside of hull) which is about what this rig would have been when at the very top of it's legs for final test.
Especially exiting when taking an evening stroll around the Helideck, which is another 30 or more meters above B/L. (136 m./446 ft.)

For comparison; Fjellstua in Aalesund, which is known for it's panoramic view "high above town", is approx. 130 m. above sea level.
The famouse London Eye is 135 m. high.

Edit: I just noticed that this is probably the same rig as in the first pic above and at about the the same position on the legs, only in the first one there is water, which make it look much "safer". I reality it is "worse", as far as forces on the legs are concerned, but well within all safety margins in both cases.

[pakarang]

Fascinating... these jacking rigs are certainly fascinating.

Great seeing the interior as well... look really spick and span, clean as a table top! Not luxurious but all in order, and with all necessities on hand.