Engineering Giants (2012–…): Season 1, Episode 2 - Gas Rig Strip-Down - full transcript
This is the Indefatigable
Lima platform.
It's the last remaining
offshore rig
in one of Britain's most productive
gas fields.
Made up of 2,500 tonnes of steel
and almost 15 miles of pipework,
it's brought over a million
cubic metres of gas up
from deep below the sea.
For almost 40 years,
it's kept us warm,
supplying gas to five million homes.
We were the young pioneers
in those days.
We were the ones bringing
oil and gas to the UK.
It was exciting.
Now, this giant
is about to be demolished.
It's going to be an immense
engineering challenge.
You just keep watching it and your
heart's going thump, thump, thump.
Diamond-coated wires
will attack two-inch-thick steel.
It allows the machine to just keep
cutting and slicing.
Gas axes burning at 3,500 degrees
will bring it to its knees.
It's an emotional time for the men
who put her up -
the North Sea Tigers.
That's 40 years of my life. Now gone.
Taking her down
will require remarkable
technical skills,
and will provide a unique chance
to see right inside
this enormous installation.
Could we get that hook reset,
please?
This is Engineering Giants.
Lima was at the heart of
the Indefatigable gas field
which was discovered in the 1960s,
70 miles off the Norfolk coast.
Now, the gas has run out,
and it's being decommissioned.
The whole project
will cost £1.5 billion
and involve the expertise
of more than 1,000 engineers.
Removing every last trace of Lima
will take nine months.
I'm Rob Bell,
I'm a mechanical engineer,
and I've always loved to get
my hands on complex machines
to discover how they work.
I'm Tom Wrigglesworth -
I'm a trained electrical engineer
with a passion for big machines.
As Lima makes her last journey, from
the North Sea back to British soil,
we'll be taking you
through every critical stage
of the engineering process.
And as she's torn apart,
we'll uncover the secrets of how
one of the world's
biggest machines works.
Few people know Lima's secrets
as well as Austin Hand.
He worked on her construction
at Lowestoft almost 40 years ago.
It started in Middlesbrough, where
it had already slipped on schedule,
so Shell decided to bring it
down here to finish it off.
Right across here? Just on a barge,
moored against the quayside, yeah.
Austin's come to meet
two other Lima veterans -
Bill Lindsay and Mick Needham.
They haven't seen each other
in over 20 years.
It's been a long time!
How are you doing? I'd like to say
we haven't changed much, but...!
LAUGHTER
I'm doing great, really. Yeah.
Probably the first time
I ever came across you
was on Lima. That's right.
And you... were the main man!
For me, what's quite special
is that you guys
were... the pioneers, really,
of North Sea gas and oil
exploration, and getting there,
getting the platforms out there.
It's a big learning curve,
for all of us -
we were only young lads.
I joined Shell in 1971
as a 22-year-old.
I'd been working power stations,
and didn't even know
what an offshore platform
looked like. Yeah.
Six years... five years later,
I'm building them.
In them days, the southern North Sea
was quite a family unit.
We didn't have too many people
coming in as, like,
international - it was mainly local
lads and you kind of stuck together.
Right. And I think
that's... these days, changed.
To your friends and family,
who weren't necessarily working
in and around the gas
and oil industry, the stories
you must have been coming home with
every week, they must have been,
"What?!" It was awfully difficult
for the families, because
if you're working in a shop or
factory, they've got a perception
of what it looks like,
but out there, they had no idea
what it was like. No idea. My oldest
girl was only about four then,
and I had to bring pictures home
of a bed and a table with food on it,
and she was happy then. But she just
thought I was working in the sea.
Mick Needham's
involvement with Lima
started when she was built.
My relationship with Lima
started in 1976,
which, er, entailed putting
three new platforms in,
and the first one was in Lima.
More than 30 years later,
Mick finds himself back out
in the North Sea,
working on Lima again,
at the very heart
of the decommissioning process.
I got a phone call saying,
"We need a company rep on board
the heavy-lift vessel Stanislav Yudin
"taking out the platforms,"
would I be interested?
And I said, "Too right, I would."
The challenge of working at sea
makes the complex decommissioning
process more costly,
more difficult and more dangerous.
Massive heavy-lifting vessel
the Stanislav Yudin,
weighing almost 25,000 tonnes,
has moored up against Lima.
This mobile demolition yard
costs half a million pounds
to hire per day,
and will be home
to the 120 engineers
who will harvest Lima from the sea.
Their first major job is to plug the
wells and sever the gas conductors.
The Lima platform had six wells,
each tapping into a separate
section of the gas reservoir,
two miles under the sea.
The only way to bore that deep
is to brace the well in sections
as it's drilled.
Each time, a smaller pipe
is passed down,
and the join is sealed
with concrete.
These are known as conductors.
Now, Lima's wells have been plugged
in four places with cement,
and the conductors
are ready to be cut.
You end up with pipes
within pipes within pipes.
So you've got
concentric rings of pipes.
Once the conductors have been cut,
you will actually see something
that's like a dartboard effect,
with concentric circles within each
other, with concrete between them.
Cutting through these materials
would be a challenge on land -
but this surgery needs to be carried
out 30 metres under the surface
of a stormy North Sea.
Matteo Mosca helped develop
an ingenious cutting solution -
one of the many methods used
in North Sea decommissioning.
So, what have we got on there?
On this wire,
which is just a steel-strand wire,
you've got embedded
these diamond bits,
these elements, which are covered
with synthetic diamond. OK.
Then, the wire is constructed
as an endless loop,
continuous, endless loop.
And it grinds its way through.
Yes, and gives, er,
a good finishing - it doesn't
alter the physical structure
of the metal, locally,
it doesn't heat it.
So, can we actually
see this... cut through?
Yes.
That's what it's made for, so...
Let's go.
Back out in the North Sea,
this process is happening
30 metres below the surface
of the water.
These cameras help guide divers
as they manoeuvre the diamond
wire-cutter into place.
MACHINE WHIRRS
Let's get cutting!
The amount of friction created
by the cutter can
heat up the steel so much
that it begins to warp,
so it has to be cooled by water.
The saw working out
on the Inde field
has the cold North Sea
to do the job.
But for this demonstration
here on land,
cold water must be sprayed on
to dissipate the heat.
The thing for me which drives home
what a clever piece of kit it is -
you've got thousands of tonnes
compressing down...
..and this cutter allows
you to cut across that
without it getting jammed.
A jam deep under water
would halt proceedings
and cost tens of thousands
of pounds to put right.
But this, because it cuts
all the way round that wire,
not just forwards,
but also above and beneath it,
it allows the machine to just
keep cutting and slicing
right the way through.
MACHINE WHIRRS
It's a really impressive cut.
On Lima, with the wells plugged
and the conductors cut,
they'll be able to move on
to a bigger challenge -
removing the 2,500-tonne platform.
This scrapping
represents the end of an era.
The North Sea veterans
who put Lima up
know how tough it will be.
34 years ago, as a young man,
Austin Hand helped
to bring it into the world.
Now, he's in charge
of decommissioning
on one of the North Sea's
biggest projects.
Is this you here?
That's me and my boss, Gordon Box,
who was the guy who actually
recruited me into Shell.
I've been involved
in that sense for 40 years,
either design and construct..
And initially, my first sort of
foray into the offshore business
was, er, Inde Lima.
That's Lima in the background?
That's it, parked in
the quayside in Lowestoft,
after we'd brought it down
from Middlesbrough.
So, that was us beginning
to get it ready to go.
The platform has to withstand
15-metre-high waves
and winds of up to 100mph.
The legs - or jacket -
is all-important,
fixing Lima to the sea bed.
Removing it is going
to be a mammoth task,
and will require as
much engineering ingenuity
as went into building her.
So, the jacket's basically a frame,
and you place it on the sea bed,
then you put piles in,
like, pinning it,
and you drive the piles with
a big hammer into the sea bed.
That is a piling hammer.
It's about 60ft high.
Now, above all these
exciting things to do,
one of my jobs was
to stand out all night
with a clicker, counting the number
of blows of the piling hammer.
You got all the good jobs!
Lima's removal from the North Sea
will involve taking away
not just the jacket,
but the piles as well.
And before that happens,
I want to understand exactly
how she was constructed
and secured out at sea.
I've got to show you how it works.
OK.
Right, so, obviously,
on Lima, this was done...
a helluva lot further out at sea!
How do they actually get it out?
They built this on land, the jacket.
Yeah?
They took it out on
a massive barge, though.
But the jacket is basically only
there as a guide for the piles.
And these are what
takes the whole force
of the topside - so they go...
slot down into each of the legs.
So, on Lima,
these piles...
were being driven
90ft into the sea bed.
Must be a very noisy job!
It IS a very noisy job!
That's why they do it so far out at
sea, so they don't disturb anyone!
Ha-ha-ha-ha!
That is going nowhere!
'With the legs firmly embedded,
the final part of the construction
'was to add the topside.'
Now, 40 years on,
removing that topside
is about to be
the biggest test so far
for Lima's decommissioning team.
Weighing in at 1,350 tonnes,
this is the heart of the rig,
where the crew lived and worked,
processing the gas
before piping it to shore.
Cutting it off the legs
will be an enormous challenge,
requiring knowledge,
skill and nerves of steel.
The problem is, how do
you cut across the legs
but still ensure the platform
stays in place until craned off?
If, for some reason,
we had a storm blow up,
and we just did a straight cut,
potentially, the wind and the weather
could vibrate the topsides
and start to move the topsides.
If it's just on a flat surface,
it could start to move,
and potentially, the last thing
I want to do is have to go fishing
to get the topsides off the sea bed.
Lives could be at stake
if they get it wrong,
and so a simple
but ingenious solution
is integrated into
how they sever the legs.
The cuts are shaped
like castle ramparts.
These cuts are absolutely genius,
and crucial to the whole
decommissioning process.
Having made the cut
through the jacket,
the topside is resting on that.
What the castellations do
is to give the whole thing
a lot more structural integrity.
But when you do need it to
be lifted, the crane comes in
and it's taken up - genius.
The final, castellated cuts are
made to Lima's legs, leaving her
1,300-tonne topside
precariously balanced on top.
The worst thing that
could happen at this stage
is a storm.
WIND BLOWS
The castellations could
be brutally put to the test.
But the morning sun
reveals that Lima's topside
is still in place.
Now, it faces a new test.
This part of the operation
is incredibly dangerous.
It uses a floating crane
that can lift 2,500 tonnes.
That's as much as
the Blackpool Tower weighs,
which is why it costs almost
half a million pounds to hire -
every day. Then, in order
to float more than
2,000 tonnes of steel back to land,
a barge is needed.
This one is as big
as a football pitch.
At this moment, there's only one
thought running through Mick's mind.
Is it going to be level? The lift
is based on complex calculations,
which allow the crane to ballast
itself against Lima's weight.
But these calculations
are estimates.
So, you're doing a theoretical model
of, er, not only
the topsides' weight,
but where the centre
of gravity of the topsides is.
And they're about to find out
how close to the truth they are.
The platform is
successfully lifted off its legs
for the first time in 30 years.
More than 1,000 tonnes of steel
are manoeuvred with precision
safely onto the barge.
With stage one complete,
the engineers will
turn their attention to the legs.
These are embedded deep into
the bedrock, and must be cut off
below the surface of the sea bed.
The task is tricky, and will require
an even more ingenious solution.
As preparation for Lima to leave the
Indefatigable gas field continues,
I want to find out more
about why she ended up there
in the first place.
For geologist John Underhill,
gas and oil exploration
is a lifetime's work.
I have this strange belief
that under the sea,
when you go drilling for oil,
there exist pools of oil,
pockets of gas, large,
you know, sealed-off sections
that we drill and tap into,
and it all comes out - is that true?
Well, it's a popular myth,
really, that we float
on a reservoir of oil - in reality,
it's solid rock, er,
with what's called pore space
between it - so, air pockets that
can be filled with gas or with oil.
These air pockets,
less than a millimetre in size,
fill up with gas
over millions of years.
The pores make this kind
of rock soft and easy to drill -
so soft, you can even feel it.
I'm moving grains of sand -
they're coming apart
and they're on my fingers,
so that's breaking apart,
that is a porous rock.
The very same rock formation
that makes up Lima's gas field
off the Norfolk coast
travels the length of England,
and emerges on land here
at Tynemouth in the north-east.
This is a core from the North Sea,
from the Inde field.
Can I hold this... this precious
ingot?
And from a sample like this,
once in the hands of the geologists,
and tested for all its components,
you can then say how rich
it is in oil or gas or...?
We can calculate how much gas
is in the Inde field, for example,
from this and from the mapping
of the seismic data.
Geologists calculated
that the Inde field
contained 5.6 trillion
cubic feet of gas -
enough to fill nearly
2 million Wembley stadiums.
Under the right conditions,
gas is formed from the remains
of organic matter,
compressed under rock
for millions of years.
This layer is known
as the carboniferous layer,
or source rock.
Above this, porous rock holds
the gas like water in a sponge,
in the gaps between its grains.
Finally, a layer of hard,
non-porous rock,
known as the sealing layer,
forms a cap,
locking in all the gas -
until someone drills a well.
There are two types
of source rock - one is oil-prone,
and comes from either marine,
erm, sediments
or lake sediments. The other type
is from woody material - coal,
that gives a gas-prone source rock.
So it's marine life
that gives us oil, and then...
land life that gives us gas.
Primarily, yes.
And here, in the cliff face
below Tynemouth Priory,
we can see how the source rock
lies beneath the sealing layer -
identical to that found
in the Inde field.
At the base,
we've got the carboniferous,
which is the... the source rock level.
Above that, we have the reservoir
unit, the yellow sands,
and above that, the recess
right at the top of the cliff
is the sealing unit,
which keeps the gas in the reservoir
underneath the North Sea,
and all three are exposed here
in this cliff line.
Out in the North Sea, with Lima's
1,300-tonne topside removed,
the next big challenge is to sever
the ten-storey-high,
1,085-tonne legs from the sea bed.
All trace of Lima must be removed
to satisfy a so-called
clean sea policy,
triggered by a dramatic event
in the North Sea 17 years ago.
The Brent Spar was a gigantic
oil storage facility,
from which oil tankers
transported the oil to shore.
By 1995,
a pipeline had been installed,
so it was no longer needed.
Shell had a plan to dump it
by towing it into the Atlantic
and sinking it.
Greenpeace saw this as a potential
environmental disaster,
so they sailed out
and took control of the Spar -
a protest that would make
international news.
In a blaze of bad publicity,
Shell reversed their decision
and instead towed it to shore
to be recycled on land
and put the rest of the Brent field
decommissioning on ice.
17 years later,
the process has restarted,
and Austin Hand, who began his
offshore career building Lima,
is in charge.
Did that kind of act
as a precedent for now
how all the fields and platforms
are decommissioned?
We thought it was a reasonable
and logical thing to do,
to take it out to sea,
2.5 miles down in the Atlantic,
and place it in this kind
of valley on the sea bed.
Er, we didn't do a very good job
of explaining that, so basically,
that resulted in the Oslo-Paris
Convention of 1998, that said,
roughly speaking, "You put them
there, you take them away."
A clean seas policy. OK.
That's what Greenpeace strove for,
and that's what they succeeded
in getting.
There's so much involved in this
that the cost of decommissioning
just must be enormous.
Austin's estimate, Austin's view -
$100 billion.
Of decommissioning... In the UK.
There are those that would say,
"I don't believe you, Austin,
"you've over-stated it."
We'll see who's right in the end.
Because of the clean seas policy,
out in the North Sea,
the Lima engineers now face
a really difficult challenge -
cutting the legs of the jacket
to remove it from the sea bed
in a way that leaves no trace
that it was ever there.
To achieve this,
the jacket legs must be cut off
three metres below the sea bed.
This means the only way
to cut the legs
is to sever them from the inside.
It's a job that demands
a very special type of cutter.
As world expert George Jack
explains, there's no blade,
no flame - just water and grit.
Is it the sea water
that you're using there?
Yeah, we filter sea water
in through our pumps,
take it up to high pressure,
and introduce the abrasive
to it as well.
That's the actual garnet
that we introduce to the water.
That's pretty hard stuff? Yeah...
'Garnet is a dark red,
silicon-based mineral.
Although large crystals
are used in jewellery,
some types possess strong atomic
bonds, which make them very hard,
and ideal as industrial abrasives.
If you don't have that
in your water,
there's not enough, er, friction
to cut through the actual metal. OK.
George is about to demonstrate
to me the power
of cutting with water and garnet.
This is the control room,
where we control the water pressure,
the grit monitor... So, what
pressure are we at, at the moment?
Just now, we're sitting at 6,000 PSI.
OK...
'That's 300-400 times greater
'than your typical
water supply at home.'
So, abrasives on.
Yes, that will put your...
introduce the grit into the system,
and the pressure comes up.
Here we go!
He-he! Look at that!
As soon as it starts coming through,
you'll see the water
coming underneath.
Who-hoah!
Now! Now you can see
it's just gone through!
So, that's 50mm of solid steel,
that's just cut. 50mm, yeah.
Compared to, say, a high-pressure
jet hose that you might get for
washing your car or doing your patio
from the hardware store... Yeah.
..if you tried to do that
with this thing,
you'd do more damage
than good, right? Oh, yeah.
The pressure we can barely read
on one of these gauges -
the first line on that,
it goes up in thousands...
I'm not sure what
kind of cut I'm expecting.
Is it going to be a clean cut?
Will it be quite jagged?
Here we go.
Wow! That's clean. That's a really
straight, clean cut.
Surprising, isn't it?
Bit of the old
Paul Daniels, Debbie McGee -
it's gone right the way through.
Yep!
So, this is not for domestic use.
No.
Not for domestic use, I'm afraid!
The Lima engineers are ready
for the high-pressure water cutter.
With the topside removed,
they're able to lower it down,
right inside the legs.
In theory, if the severance
isn't complete,
the crane could pull
the Stanislav Yudin over.
In practice,
fail-safe mechanisms would prevail.
But an incomplete severance
could still cost millions.
We control it from the topside using
hydraulics and everything. OK.
And it'll cut... do a 360 degrees,
sub-sea,
just three metres below the sea bed.
Before they begin the cutting,
every precaution must be taken.
The system is pressurised
to 6,000lb per square inch.
Any leak or breach could be deadly.
An exclusion zone around the cutter
is strictly enforced.
We've got high-pressure hoses
running across the deck.
If you put your hand up like that...
you're not going to have
anything left.
Calculations estimate
that the 360-degree cut
of each leg should take 75 minutes.
All Mick can do now
is time it and hope.
Once the allotted time
has been given to each leg,
special slings are attached.
So all the slings are...
They're not just something
you get off a shelf.
All the slings are engineered
and designed
and built to the length required.
Now the crane must ballast itself
against an unknown payload.
Up to 300 tonnes of extra weight
in marine life
could have accumulated
over four decades,
making the jacket 1,400 tonnes -
as heavy as seven jumbo jets.
All this makes the calculations for the
stability of the crane more and more difficult,
puts the ballasting power of the
Stanislav Yudin yet further to the test,
and her stability in more jeopardy.
And then the big,
tense moment for everybody...
..because we are now going to start
to lift the jacket.
But there's one thing we can't do -
we can't actually 100% guarantee
they're cut by going
and having a look at them.
You hear the crane driver,
he starts taking the weight
on the crane...
..1,200, 1,400 tonnes,
somewhere in that region.
And if he gets to 1,400 tonnes
and then he starts saying,
"I'm at 1,450 now,"
you're thinking, "I hope this
is going to move shortly."
And your heart's probably
going "thump, thump, thump."
And then, all of a sudden,
it just seems to go, "Ooh!"
And it's a great sight, that,
and it's a great relief.
After the final lift, engineers
work through the night to fasten
Lima safely to the barge upon which
she'll make her final journey.
And that was it,
it was an end of an era
for, not only myself,
but for so many people
that have worked on the Inde field
throughout the last 40 years.
In the dead of night, she leaves
the Inde field behind for ever
and sets off on the 200-mile
journey home to the north-east.
Mick's relationship with Lima
has finally come to an end.
Inde produced for so long,
it brought lots of people work,
and, more than that, lots of great
friends and happy memories.
I think that's what'll stick.
I'm now choking up.
Oh, dear.
I can't believe it.
Excuse me.
But, for Lima, this marks the start
of the next phase of deconstruction.
As dawn breaks over the horizon,
Lima arrives at the mouth
of the River Tyne.
From here, she'll be taken to the famous
Swan Hunter shipyard for demolition.
It's amazing to think something like
Lima, how important that was to us.
We just don't really
consider that at all, really.
It's delivering all that gas to our homes,
keeping us warm, cooking our food...
Well, the Inde field
actually produced enough gas
in its lifetime to power the UK
for a year and a half.
Just in one gas field? Yeah.
At the Swan Hunter shipyard,
they must wait for the tide
to be just the right height,
so the barge is level with the quay.
Only then can the painstaking
process of sliding
over 2,000 tonnes of steel
off the barge on to land begin.
You don't see one of them
come over every day, do you?
Four remotely controlled bogies,
with a total of 56 axles,
each capable of supporting
36 tonnes of weight...
Fantastic.
..manoeuvre Lima into her
final resting place.
Now the next chapter in her story
is about to begin.
Ivan Rayne is Geordie born and bred,
and is another person
whose relationship with Lima
and her sister platforms goes back
to their construction in the 1970s.
I bet you didn't have to wear all this
kind of stuff back in the '70s, did you?
Yeah, we did,
but once you got offshore,
if you ever mentioned
the word "safety,"
you were on the next
helicopter home again.
He, too, has come a complete circle.
He's now here to oversee the
demolition and recycling of Lima.
All these pipes and valves and the
kind of meat, everything we can see,
it's all dedicated to getting
that gas up and out of here.
The main function of this platform
is to gather gas from the seabed,
and the gas would be brought up
through six pipes,
brought into this system here,
and then redirected to another
complex, where it is collected
and then it's sent to
the UK mainland for refining.
Then it gets redistributed
throughout the UK,
then it comes into your house
and that's what you use
for cooking your roast beef
on a Sunday.
For Veolia's recycling team
in charge of the demolition,
this is no ordinary take-down job.
So, this has been out
in the North Sea for 40 years.
Where do you start in taking it
all apart and recycling it?
The helideck will be cut off
and pulled over,
then we'll start dismantling it,
section by section.
Once that's flattened,
they'll start cutting it up into
very manageable pieces,
and the smaller the pieces,
the better the value they get for
recycling for transport off the site.
All right,
so now we're talking money.
Typically, what are we looking at
for recycling this whole platform?
You could be looking at anything
from £180-£200,000 scrap value.
After 40 years of service,
providing gas to millions of people,
and jobs and even a home
to hundreds of North Sea Tigers,
Lima is finally about to be brought
to her knees.
First, her infrastructure
is weakened by strategic cuts.
Next, it's time for the excavators
to really get to work.
Steel wires are attached
to the helideck
and the machines go into reverse.
This red accommodation module
is next for demolition.
Its fixings to Lima's frame
have been severed,
and the excavators are standing by.
'Mick Cubitt spent four years
living and working
'on Lima
as an electrical engineer.
'It's almost 19 years to the day
since she last saw her.'
That is incredible.
It's like a bomb...
A bomb has hit the place.
In fact,
it's bordering on unrecognisable.
I don't want to pull any more
emotional punches on you,
but I think that is
your old bedroom,
that red tin shack over that.
I'm afraid so. I spent several... in
effect, the equivalent to two years' worth.
So... Four years, half on,
half off. That's right.
Some 700 nights spent
in that little tin box.
We're about to walk into
your accommodation block,
this is home sweet home. Home sweet
home looks fairly devastating to me.
It's really had the insides
ripped out of it.
So this was the living area, was it?
This is where you passed the time?
Well, prior to the introduction
of satellite television,
we used to show films that were
hired in by the company.
Like your own little Blockbuster!
Yes!
So, Mick, this must have been pretty
cramped. How many people lived in here?
This was accommodation for eight
people, two lots of bunks.
Um, the shower for all four
was in here.
That's the shower tray,
with a wash basin just here.
Shower, wash basin.
That was your emergency exit.
So, it's the middle of the night,
you're asleep in your comfortable
abode and there's an emergency alarm.
The worst-case scenario.
What's the order of service?
Three offs.
The three offs being block off,
we would block in all the wells, stop
the gas coming onto the platform.
You would then vent off. What's
the third off? You just BLEEP off!
Follow me. OK.
Quickly, Mick,
it's an emergency situation!
For Mick's Lima colleagues,
reunited in Lowestoft for the first
time in over 20 years, all that's
left are photos and shared memories
of their incredible offshore lives.
Is this you? That is me on Lima.
How many times would you have been
offshore at that stage, do you reckon?
Probably not many. We used to fish,
didn't we, Tony?
There is some entertainment to
be had. Made our own entertainment.
What was the food supplies like,
did you eat well?
Ate very well. You would have a
choice of a fillet steak, a bit of fish.
That's a decent spread, isn't it?
It is indeed. Christmas crackers.
Explosive devices offshore!
LAUGHTER
If you had a good chef, you had a good
platform, and you'd a productive platform.
One thing I really take away
from this whole process
is it isn't just the hardware, it
isn't just the steel and everything.
It's the family. It's the family of all
the people who've built it, worked on it.
How does it feel now that that particular
field and Lima platform is not there any more?
Does it kind of sit with you,
does it rest with you, or...?
When you finish, you think, "That's
40 years of my life. Now gone."
You just realise how old
you're bloody getting!
Back at the Swan Hunter shipyard,
another relic of the glory days
of the North Sea has been uncovered,
a stark reminder of just how
treacherous it can be.
This looks like a horror story, but
I believe it was just a helideck,
when they removed it,
it smashed into the front.
But this is your survival raft. Yes, this was the
Brucker capsule, as it was known, on the platform.
Awful thing to steer, being circular,
and an awful thing to ride in.
Were you the captain?
I've done the coxon's training on here, and I've
been to see with guys who are happily throwing up,
and it is not the best place to be,
even with a dozen guys in,
when you've got a couple of them
throwing up into their hard hat.
I'm hoping that years of training
means that my Lima veterans
have grown stronger stomachs,
because I'm about to get my first
taste of the Brucker pod experience.
This is exactly the kind of one
you had up on Lima, is it?
Absolutely. Yes, identical.
Identical.
Luxurious, was it?
No! That's how we became friends!
THEY LAUGH
Pods like these have
safely evacuated
more than 2,000 people in over
60 incidents around the world
since Lima was built.
How long is it since you guys
have been in one of these?
For me, it would have been 1978,
in this particular type.
I've been given the job
of releasing the capsule,
and it's fair to say that the speed of
the response takes me by surprise.
Right, we're off.
They were designed for
the Gulf of Mexico,
but the bobbing doughnut was no match for the
waves and currents of an undulating North Sea.
The survival pods, still vital
for an industry which
has claimed hundreds of lives,
are now usually boat-shaped.
I'm being shown at the ropes
by Nick Goldspink,
who's been teaching North Sea Tigers
how to navigate these pods
since 1989.
I mean, we're moving around like
a boat but, still, this round shape
seems like a very odd design
for a boat to me.
Yeah, it's partly to do with strength
and it's partly to do with
ease of operation.
The traditional style of lifeboat has
got a cable at the front and the back,
and there's a chance
that that can hang up.
There is no chance and no possibility
of that with this shape of boat.
Obviously, there is a compromise
to the shape,
and that is that they do
bob around like a cork.
Round boat, though,
how do you even steer this?
Yeah, well, that is more difficult
than a traditional lifeboat shape,
but the advantage to that
is they are very manoeuvrable.
But she's steered, basically,
from the tiller, here,
which again,
is unusual in a lifeboat,
to steer a boat from the front.
If you were to evacuate,
how long would you be able
to survive in a craft like this?
A fairly long while would
be the answer to that.
I mean, there's enough water
and food for a week.
I would not want to be stuck in here
for a week with 27 other people.
You'd get to know them fairly well
fairly quickly!
You would become quite an intimate,
an intimate team.
So, how was that, gents?
Bring back a few memories? Yes.
I have to say, 20 years on, I never
thought I'd be back in one of them!
Back on Tyneside, there's
nothing shipshaped about Lima,
which is being slowly cut down
girder by girder,
making it no longer possible to trace
the pathway that gas would have taken,
snaking through miles of Lima's pipework
from under the sea to our kitchen hobs.
So, to solve the mystery
of how she worked,
I'm going to see an offshore
platform in action
and trace the fossil fuel route.
I'm bit anxious, because I've never
been on a helicopter before.
Thanks to gas and oil, Aberdeen
heliport is Europe's busiest,
ferrying almost half a million
passengers offshore every year.
Across the North Sea, more than
100 lives have been lost
since air transfers began,
which is why every possible
safety technique is used.
I'm terrified, truth be known.
Absolutely terrified.
In the event
of the helicopter ditching,
this suit will increase my survival
time in the freezing North Sea
from just minutes
to about seven hours,
but I hope I don't have
to put it to the test.
After an hour of seeing nothing
but sea, a platform comes into view.
100 miles offshore from Aberdeen,
in the northern North Sea,
this is Nelson,
which produces both gas and oil.
The fossil fuel's pathway on Nelson
is very similar to Lima's
gas pathway,
so I'm going to track the route
from under the sea to our homes
and explore how current
technology works.
While Lima had six wells,
Nelson has drilled 28.
Nelson's manager, Nick Macleod,
is going to show me the drill floor.
Wow!
Pretty impressive drills there!
That is impressive.
Our wells here can go down
as far as 20,000 feet.
20,000 feet? Yeah.
And eventually we get down to what's
called the pay zone, which...
Pay zone? Yeah, the pay zone -
that's where the money is!
Yeah, yeah. That's where the oil
and gas is. OK, what happens then?
It all spurts up, doesn't it?
And everyone cheers!
In the old days.
Hopefully not these days!
The first crucial stage for the fuel
that emerges is the well bay.
Everything is moving about
and juddering. It's really noisy.
Absolutely unbelievable.
It's unbelievable to consider that
they've made this size of machine.
It is even more incredible
when you realise that we're
100 miles off the coast.
Production engineer Murdo MacDonald
is here to explain the first step
of the fossil fuel's pathway...
Oh! There's not a lot
of room in here.
..which involves something known
in the trade as a Christmas tree.
Why is it actually called
a Christmas tree?
Maybe it's because they look like
they've got branches coming off.
You've got all the gauges
hanging off...
You've got quite an imagination
if you...
Aye, you've got quite a bit...
You have to with two weeks offshore!
When a well's drilled,
the raw fuel comes up the conductors
into the well bay.
On Lima, this was gas.
On Nelson, it's gas and oil.
Here, the Christmas trees, large
assemblies of valves and gauges,
help control the flow of oil and gas
entering the platform.
I'm ready for my first offshore job.
Five turn!
Oh, one... two... three... four...
Five turns!
What have I done? You've just
closed the choke in about 5%.
Just closed the choke in 5%?
Which has restricted the oil
flow coming up...? Absolutely.
Stage two of the pathway
is all about separating
what emerges from the well
into its constituent parts.
It's like science fiction film.
When a well is drilled, oil comes up
the conductors into the well bay,
but it's not pure oil.
It's a mixture of oil,
gas and water.
In order to extract the valuable oil
and collect the gas,
the whole mixture is sent
to one of the most important devices
on the platform - the separator.
I've made a model
of Nelson's separator,
to explain to Rob how it works.
It's bafflingly simple.
We have here a bucket,
which to the casual observer
appears to be a generic brand of
cola mixed with vegetable oil,
which is actually exactly the same
as oil, water and gas, all right?
That's from the bottom of the sea.
We've got a pump but, normally, that's got
enough pressure to be forcing itself up.
Exactly. That would be pushed up
under its own steam.
So, what you do,
you separate them out.
The gas will naturally
float off to the top. Yes.
Lighter than both of them. So that will
normally be tapped and off into wherever else...
Exactly, that'll be tapped
and processed, yeah.
Water is heavier than oil.
So, this weir is very important,
because the oil floats on the water.
OK, you see that easily here.
So, the brown stuff is the water
and the creamy stuff is your oil?
Exactly. So, because the oil
is floating on the water,
it flows over the top of this weir,
creating this secondary chamber
here, which is pretty much all oil.
So, coming out of here
you get pure oil,
coming out the bottom of this
section you get flat cola -
or water. Yeah.
Coming out the top, gas. Gas.
This separation stage of the fossil
fuel's pathway is vitally important,
because it tells the energy company
how much gas and oil they are producing.
To do this, every day, each well
is taken out of production
and diverted into
the test separator.
Tom, pleased to meet you.
You too. How's it going?
In the control room, Pete O'Connor
is monitoring results.
So, that's the production
valve there -
the diverter valve, which is open.
That's the test one, which is shut.
So, by putting it into
the test separator,
it lets us know how
the well's performing,
how much oil it's producing,
how much water
and how much gas it's producing.
All our wells, now,
are starting to water out.
They're all over 80% water.
And that didn't used to be the case?
No. No, they all gradually, they
gradually decline in oil production.
So, the test separator
is actually testing the mix
of oil, to gas, to water?
For each individual well. Yeah.
We have a spot rate there,
which, at the moment,
can tell you we're doing
19,357 barrels, near enough,
today, at the moment. Wow!
At that rate, Nelson produces oil
worth around £1.5 million a day.
Not a bad return.
The third and final stage
of the fossil fuel's pathway
is exporting it.
Water is cleaned
and pumped overboard.
Oil is cleaned and then pumped
down the export pipeline to shore,
but it's not all over for the gas.
Some is exported to gas terminals.
Excess is burnt off
on the iconic flare stack.
But most of it is diverted
to something known as the gas lift
to do an important job.
Because of the weight of the ocean
on this trapped reservoir
of hydrocarbons,
it's all under pressure...
Which is kind of like this.
Ha-ha-ha!
So, the moment the drill pierces
it, BOOM! Wow, you've got oil.
The oil comes out. Now, obviously,
quite soon it loses pressure.
So, once they've been
tapping the oil off...
So, it becomes, like, the field
becomes flat? Yes, exactly.
It becomes flat,
it becomes devoid of pressure.
Yeah. So, what you do,
instead of pumping it up... Yeah.
..you push gas down
into the reservoir,
which makes the oil light
because it's got gas in it,
which then sends it back up.
You basically make the world's
biggest SodaStream! Yeah!
The gas collected from the separator
is compressed, repressurised
and then reinjected back down
the well via the Christmas tree,
forcing more precious oil up.
The force required
to do this is huge.
On the platform, Murdo shows me
where they get it from.
It's a gas compressor,
which is essentially a jet engine,
and it's one of the noisiest things
I've ever experienced.
SHOUTING: The engine drives
the power turbine,
that drives the gas compressor.
The gas compressor takes the pressure
from five bar in the separator,
takes it all the way to 147 bar.
'That's 147 times
atmospheric pressure.'
That 147 bar is then used
in the header to reinject
back down the wells and lift
the oil back up again.
They've a powerful blow,
those jet engines.
I'd say it's quite a blow, all right.
But while Nelson's conductors
are still full of North Sea gas,
Lima's conductors now lie severed
from the rest of the platform
on the quayside at the
Swan Hunter yard near Newcastle.
Demolishing them
is going to be a feat in itself.
Because of the way the wells
are drilled and constructed,
they end up with pipes
within pipes, within pipes,
all sealed with thick
layers of cement.
Turning this into small pieces
of scrap metal requires
a process known as bombing.
First, the gas axe is used
to cut along both sides
of the long steel conductor.
Then, to get at the inner pipes,
the excavator steps in.
Once it's made short work
of the concrete,
the inner steel pipes are revealed,
and the process starts over again.
With over a third of a kilometre
of conductors to scrap,
it's a lengthy process.
Meanwhile, on the other side
of the yard, only Lima's legs -
or jacket as it's known -
still remain.
Built from over 1,000 tonnes
of high grade steel,
it must be broken up into
small chunks to be recycled.
The first stage is to bring
the structure to its knees.
Strategic cuts must be made
so the legs collapse neatly.
But it's a dangerous job.
As soon as a cut is made,
the platform is weakened
and may fall at any time.
Are you guys responsible for felling
the legs? Yes, we are.
I wouldn't like to be the guy
who does the final cut.
Who's in charge of that?
Whoever wants to do it.
The backside gets a bit twitchy
when the final cut's made.
I can well understand.
I think if it was me,
the moment the axe is finished,
I would be turning and running.
Do you actually...?
Oh, no. There's no need to run.
In a carefully controlled
and calculated procedure,
towlines attached to the top of the
jacket will be used to pull it over.
This is the first time this method
has been attempted
anywhere in the world.
We attach two ropes either
side of the jacket
and a safety rope to the very back
of the jacket,
just to stop the back legs
toppling the wrong way.
The engineers have put down a bed of
earth for the legs to collapse onto,
to cushion the impact.
They've got two lines, haven't they?
Yeah, two pulling lines.
These guys will take
the tension up on the wire.
Just give it a little tug.
It's quite exciting,
just the anticipation of it.
Before it comes down.
Everything clear? RADIO: 'Clear.'
Don't let anything in now, cos
we're about ready. 'All clear, Mick.'
If the 30-metre-high back legs were
to fall in the wrong direction,
they could land on a factory
behind the shipyard.
Excited to see these come down?
I love it. Brilliant.
Well done. Brilliant.
That was awesome. Congratulations.
And that's the way to do it.
RADIO: 'Perfect, Ned.'
The demolition of this jacket
for recycling is the final act
in the scrapping
of the Lima platform.
'Although veteran Lima engineer
Austin Hand
'is working in decommissioning,
'he has not seen Lima - the platform
he cut his teeth on - for 20 years.'
There she is now.
Wow.
I'm so used to building things,
so to see it dismantled
and in pieces is just...
You're probably quite used to it
in this condition, in a sense.
I can still see the module, yeah.
Just on a different curve
of its life. Yeah.
That really reminds me
of going on and off
that barge for months.
Getting it completed,
just walking over the gangplank
and working 12 or 14 hour days,
every day.
But it was fun and exciting. I'll
bet. Yeah. That gives me a buzz.
We were the young pioneers
in those days.
We were the ones bringing oil and gas
to the UK. It was exciting.
Good memories.
So, we've seen, Austin,
as this process has unfolded,
the huge machine of Lima
being reduced to small piles
of steel rubble.
I was surprised to see
so much timber on show.
Can you tell me about this?
They used to say in my day that
the rigs were made of wood
and men were made of steel,
but that's not actually true.
What this was is we covered the main
steel deck with this timber
so that when you were lifting
stuff off the supply boats
and landing it on the platform,
you had some absorption material
to avoid damaging the deck
or even the container.
So, all this timber here
was to provide you
with a huge cushioned area
to protect the whole thing.
Like a massive chopping board,
in way. Absolutely, yeah.
This steel tubing once formed the
jacket that supported the topside.
It's now been broken up
into sections, ready to be recycled.
'But to the expert eye,
even these fragments reveal
'the challenges of these early
pioneering designs.'
In the '70s, sometimes the quality
wasn't that great.
This is a good example here.
This is a very tough angle for
a welder to get in at these points.
Yeah, you get right down in there.
Exactly. So, in an ideal world,
that brace would have been
at less of an angle.
Very often, the designers just wanted
it to be structurally robust.
Then, when it arrived for us to deal
with in the construction yard,
you think,
"Wow, why did they do that?"
Yes, so on paper, mathematically,
it makes perfect sense.
Exactly, but sometimes
it wasn't constructible.
But again,
this was a learning process.
We'd feed that back in
to the next jacket and say,
"Can we do this slightly
differently?"
That's how we evolved the industry,
getting better and better
and ensuring these wells
were sound and solid.
All these things had to be
considered, even with a relatively
simple structure like a jacket.
For the final time, the excavators
pull on Lima's infrastructure
to bring down her last storey.
The legs are going to go.
There she goes.
It's very sad to see that, something
that you built when you were
a 25-year-old, and you're pulling it
to bits when you're a 59-year-old.
It just shows you, time moves on.
Nothing stands still.
Lima is now unrecognisable,
just heaps of rubble and thousands
of tonnes of scrap steel.
Amazingly, some 99% of this
will be recycled.
The wood from the decks is pulped
and made into paper.
Even the 300 tonnes of algae
that collected on the legs
will be recycled for compost.
But most lucrative is the steel.
Once the various grades
have been separated out,
it's then smelted and made into
new girders and pipes.
Fittingly, just half a mile
down the road,
steel from the smelted remains
of machines like Lima
are being used to build this...
..a brand-new 21st-century platform.
To put it in perspective, whereas
Lima weighed a few hundred tonnes,
this weighs in at a whopping
12,000 tonnes.
Platforms like this are giving
the North Sea a new lease of life.
But Lima and its gas field
are now just a memory.
Removing it cost more
than £200 million, took two years
and over a million staff hours
to recycle 2,000 tonnes of steel,
311 tonnes of algae,
find homes for two generators
and scrap two toilets
and 12 well-worn bunks.
Ironically, some of
the North Sea Tigers who pioneered
offshore platform installation
are now involved
in the biggest new North Sea
industry -
taking them back down again.
Lima platform.
It's the last remaining
offshore rig
in one of Britain's most productive
gas fields.
Made up of 2,500 tonnes of steel
and almost 15 miles of pipework,
it's brought over a million
cubic metres of gas up
from deep below the sea.
For almost 40 years,
it's kept us warm,
supplying gas to five million homes.
We were the young pioneers
in those days.
We were the ones bringing
oil and gas to the UK.
It was exciting.
Now, this giant
is about to be demolished.
It's going to be an immense
engineering challenge.
You just keep watching it and your
heart's going thump, thump, thump.
Diamond-coated wires
will attack two-inch-thick steel.
It allows the machine to just keep
cutting and slicing.
Gas axes burning at 3,500 degrees
will bring it to its knees.
It's an emotional time for the men
who put her up -
the North Sea Tigers.
That's 40 years of my life. Now gone.
Taking her down
will require remarkable
technical skills,
and will provide a unique chance
to see right inside
this enormous installation.
Could we get that hook reset,
please?
This is Engineering Giants.
Lima was at the heart of
the Indefatigable gas field
which was discovered in the 1960s,
70 miles off the Norfolk coast.
Now, the gas has run out,
and it's being decommissioned.
The whole project
will cost £1.5 billion
and involve the expertise
of more than 1,000 engineers.
Removing every last trace of Lima
will take nine months.
I'm Rob Bell,
I'm a mechanical engineer,
and I've always loved to get
my hands on complex machines
to discover how they work.
I'm Tom Wrigglesworth -
I'm a trained electrical engineer
with a passion for big machines.
As Lima makes her last journey, from
the North Sea back to British soil,
we'll be taking you
through every critical stage
of the engineering process.
And as she's torn apart,
we'll uncover the secrets of how
one of the world's
biggest machines works.
Few people know Lima's secrets
as well as Austin Hand.
He worked on her construction
at Lowestoft almost 40 years ago.
It started in Middlesbrough, where
it had already slipped on schedule,
so Shell decided to bring it
down here to finish it off.
Right across here? Just on a barge,
moored against the quayside, yeah.
Austin's come to meet
two other Lima veterans -
Bill Lindsay and Mick Needham.
They haven't seen each other
in over 20 years.
It's been a long time!
How are you doing? I'd like to say
we haven't changed much, but...!
LAUGHTER
I'm doing great, really. Yeah.
Probably the first time
I ever came across you
was on Lima. That's right.
And you... were the main man!
For me, what's quite special
is that you guys
were... the pioneers, really,
of North Sea gas and oil
exploration, and getting there,
getting the platforms out there.
It's a big learning curve,
for all of us -
we were only young lads.
I joined Shell in 1971
as a 22-year-old.
I'd been working power stations,
and didn't even know
what an offshore platform
looked like. Yeah.
Six years... five years later,
I'm building them.
In them days, the southern North Sea
was quite a family unit.
We didn't have too many people
coming in as, like,
international - it was mainly local
lads and you kind of stuck together.
Right. And I think
that's... these days, changed.
To your friends and family,
who weren't necessarily working
in and around the gas
and oil industry, the stories
you must have been coming home with
every week, they must have been,
"What?!" It was awfully difficult
for the families, because
if you're working in a shop or
factory, they've got a perception
of what it looks like,
but out there, they had no idea
what it was like. No idea. My oldest
girl was only about four then,
and I had to bring pictures home
of a bed and a table with food on it,
and she was happy then. But she just
thought I was working in the sea.
Mick Needham's
involvement with Lima
started when she was built.
My relationship with Lima
started in 1976,
which, er, entailed putting
three new platforms in,
and the first one was in Lima.
More than 30 years later,
Mick finds himself back out
in the North Sea,
working on Lima again,
at the very heart
of the decommissioning process.
I got a phone call saying,
"We need a company rep on board
the heavy-lift vessel Stanislav Yudin
"taking out the platforms,"
would I be interested?
And I said, "Too right, I would."
The challenge of working at sea
makes the complex decommissioning
process more costly,
more difficult and more dangerous.
Massive heavy-lifting vessel
the Stanislav Yudin,
weighing almost 25,000 tonnes,
has moored up against Lima.
This mobile demolition yard
costs half a million pounds
to hire per day,
and will be home
to the 120 engineers
who will harvest Lima from the sea.
Their first major job is to plug the
wells and sever the gas conductors.
The Lima platform had six wells,
each tapping into a separate
section of the gas reservoir,
two miles under the sea.
The only way to bore that deep
is to brace the well in sections
as it's drilled.
Each time, a smaller pipe
is passed down,
and the join is sealed
with concrete.
These are known as conductors.
Now, Lima's wells have been plugged
in four places with cement,
and the conductors
are ready to be cut.
You end up with pipes
within pipes within pipes.
So you've got
concentric rings of pipes.
Once the conductors have been cut,
you will actually see something
that's like a dartboard effect,
with concentric circles within each
other, with concrete between them.
Cutting through these materials
would be a challenge on land -
but this surgery needs to be carried
out 30 metres under the surface
of a stormy North Sea.
Matteo Mosca helped develop
an ingenious cutting solution -
one of the many methods used
in North Sea decommissioning.
So, what have we got on there?
On this wire,
which is just a steel-strand wire,
you've got embedded
these diamond bits,
these elements, which are covered
with synthetic diamond. OK.
Then, the wire is constructed
as an endless loop,
continuous, endless loop.
And it grinds its way through.
Yes, and gives, er,
a good finishing - it doesn't
alter the physical structure
of the metal, locally,
it doesn't heat it.
So, can we actually
see this... cut through?
Yes.
That's what it's made for, so...
Let's go.
Back out in the North Sea,
this process is happening
30 metres below the surface
of the water.
These cameras help guide divers
as they manoeuvre the diamond
wire-cutter into place.
MACHINE WHIRRS
Let's get cutting!
The amount of friction created
by the cutter can
heat up the steel so much
that it begins to warp,
so it has to be cooled by water.
The saw working out
on the Inde field
has the cold North Sea
to do the job.
But for this demonstration
here on land,
cold water must be sprayed on
to dissipate the heat.
The thing for me which drives home
what a clever piece of kit it is -
you've got thousands of tonnes
compressing down...
..and this cutter allows
you to cut across that
without it getting jammed.
A jam deep under water
would halt proceedings
and cost tens of thousands
of pounds to put right.
But this, because it cuts
all the way round that wire,
not just forwards,
but also above and beneath it,
it allows the machine to just
keep cutting and slicing
right the way through.
MACHINE WHIRRS
It's a really impressive cut.
On Lima, with the wells plugged
and the conductors cut,
they'll be able to move on
to a bigger challenge -
removing the 2,500-tonne platform.
This scrapping
represents the end of an era.
The North Sea veterans
who put Lima up
know how tough it will be.
34 years ago, as a young man,
Austin Hand helped
to bring it into the world.
Now, he's in charge
of decommissioning
on one of the North Sea's
biggest projects.
Is this you here?
That's me and my boss, Gordon Box,
who was the guy who actually
recruited me into Shell.
I've been involved
in that sense for 40 years,
either design and construct..
And initially, my first sort of
foray into the offshore business
was, er, Inde Lima.
That's Lima in the background?
That's it, parked in
the quayside in Lowestoft,
after we'd brought it down
from Middlesbrough.
So, that was us beginning
to get it ready to go.
The platform has to withstand
15-metre-high waves
and winds of up to 100mph.
The legs - or jacket -
is all-important,
fixing Lima to the sea bed.
Removing it is going
to be a mammoth task,
and will require as
much engineering ingenuity
as went into building her.
So, the jacket's basically a frame,
and you place it on the sea bed,
then you put piles in,
like, pinning it,
and you drive the piles with
a big hammer into the sea bed.
That is a piling hammer.
It's about 60ft high.
Now, above all these
exciting things to do,
one of my jobs was
to stand out all night
with a clicker, counting the number
of blows of the piling hammer.
You got all the good jobs!
Lima's removal from the North Sea
will involve taking away
not just the jacket,
but the piles as well.
And before that happens,
I want to understand exactly
how she was constructed
and secured out at sea.
I've got to show you how it works.
OK.
Right, so, obviously,
on Lima, this was done...
a helluva lot further out at sea!
How do they actually get it out?
They built this on land, the jacket.
Yeah?
They took it out on
a massive barge, though.
But the jacket is basically only
there as a guide for the piles.
And these are what
takes the whole force
of the topside - so they go...
slot down into each of the legs.
So, on Lima,
these piles...
were being driven
90ft into the sea bed.
Must be a very noisy job!
It IS a very noisy job!
That's why they do it so far out at
sea, so they don't disturb anyone!
Ha-ha-ha-ha!
That is going nowhere!
'With the legs firmly embedded,
the final part of the construction
'was to add the topside.'
Now, 40 years on,
removing that topside
is about to be
the biggest test so far
for Lima's decommissioning team.
Weighing in at 1,350 tonnes,
this is the heart of the rig,
where the crew lived and worked,
processing the gas
before piping it to shore.
Cutting it off the legs
will be an enormous challenge,
requiring knowledge,
skill and nerves of steel.
The problem is, how do
you cut across the legs
but still ensure the platform
stays in place until craned off?
If, for some reason,
we had a storm blow up,
and we just did a straight cut,
potentially, the wind and the weather
could vibrate the topsides
and start to move the topsides.
If it's just on a flat surface,
it could start to move,
and potentially, the last thing
I want to do is have to go fishing
to get the topsides off the sea bed.
Lives could be at stake
if they get it wrong,
and so a simple
but ingenious solution
is integrated into
how they sever the legs.
The cuts are shaped
like castle ramparts.
These cuts are absolutely genius,
and crucial to the whole
decommissioning process.
Having made the cut
through the jacket,
the topside is resting on that.
What the castellations do
is to give the whole thing
a lot more structural integrity.
But when you do need it to
be lifted, the crane comes in
and it's taken up - genius.
The final, castellated cuts are
made to Lima's legs, leaving her
1,300-tonne topside
precariously balanced on top.
The worst thing that
could happen at this stage
is a storm.
WIND BLOWS
The castellations could
be brutally put to the test.
But the morning sun
reveals that Lima's topside
is still in place.
Now, it faces a new test.
This part of the operation
is incredibly dangerous.
It uses a floating crane
that can lift 2,500 tonnes.
That's as much as
the Blackpool Tower weighs,
which is why it costs almost
half a million pounds to hire -
every day. Then, in order
to float more than
2,000 tonnes of steel back to land,
a barge is needed.
This one is as big
as a football pitch.
At this moment, there's only one
thought running through Mick's mind.
Is it going to be level? The lift
is based on complex calculations,
which allow the crane to ballast
itself against Lima's weight.
But these calculations
are estimates.
So, you're doing a theoretical model
of, er, not only
the topsides' weight,
but where the centre
of gravity of the topsides is.
And they're about to find out
how close to the truth they are.
The platform is
successfully lifted off its legs
for the first time in 30 years.
More than 1,000 tonnes of steel
are manoeuvred with precision
safely onto the barge.
With stage one complete,
the engineers will
turn their attention to the legs.
These are embedded deep into
the bedrock, and must be cut off
below the surface of the sea bed.
The task is tricky, and will require
an even more ingenious solution.
As preparation for Lima to leave the
Indefatigable gas field continues,
I want to find out more
about why she ended up there
in the first place.
For geologist John Underhill,
gas and oil exploration
is a lifetime's work.
I have this strange belief
that under the sea,
when you go drilling for oil,
there exist pools of oil,
pockets of gas, large,
you know, sealed-off sections
that we drill and tap into,
and it all comes out - is that true?
Well, it's a popular myth,
really, that we float
on a reservoir of oil - in reality,
it's solid rock, er,
with what's called pore space
between it - so, air pockets that
can be filled with gas or with oil.
These air pockets,
less than a millimetre in size,
fill up with gas
over millions of years.
The pores make this kind
of rock soft and easy to drill -
so soft, you can even feel it.
I'm moving grains of sand -
they're coming apart
and they're on my fingers,
so that's breaking apart,
that is a porous rock.
The very same rock formation
that makes up Lima's gas field
off the Norfolk coast
travels the length of England,
and emerges on land here
at Tynemouth in the north-east.
This is a core from the North Sea,
from the Inde field.
Can I hold this... this precious
ingot?
And from a sample like this,
once in the hands of the geologists,
and tested for all its components,
you can then say how rich
it is in oil or gas or...?
We can calculate how much gas
is in the Inde field, for example,
from this and from the mapping
of the seismic data.
Geologists calculated
that the Inde field
contained 5.6 trillion
cubic feet of gas -
enough to fill nearly
2 million Wembley stadiums.
Under the right conditions,
gas is formed from the remains
of organic matter,
compressed under rock
for millions of years.
This layer is known
as the carboniferous layer,
or source rock.
Above this, porous rock holds
the gas like water in a sponge,
in the gaps between its grains.
Finally, a layer of hard,
non-porous rock,
known as the sealing layer,
forms a cap,
locking in all the gas -
until someone drills a well.
There are two types
of source rock - one is oil-prone,
and comes from either marine,
erm, sediments
or lake sediments. The other type
is from woody material - coal,
that gives a gas-prone source rock.
So it's marine life
that gives us oil, and then...
land life that gives us gas.
Primarily, yes.
And here, in the cliff face
below Tynemouth Priory,
we can see how the source rock
lies beneath the sealing layer -
identical to that found
in the Inde field.
At the base,
we've got the carboniferous,
which is the... the source rock level.
Above that, we have the reservoir
unit, the yellow sands,
and above that, the recess
right at the top of the cliff
is the sealing unit,
which keeps the gas in the reservoir
underneath the North Sea,
and all three are exposed here
in this cliff line.
Out in the North Sea, with Lima's
1,300-tonne topside removed,
the next big challenge is to sever
the ten-storey-high,
1,085-tonne legs from the sea bed.
All trace of Lima must be removed
to satisfy a so-called
clean sea policy,
triggered by a dramatic event
in the North Sea 17 years ago.
The Brent Spar was a gigantic
oil storage facility,
from which oil tankers
transported the oil to shore.
By 1995,
a pipeline had been installed,
so it was no longer needed.
Shell had a plan to dump it
by towing it into the Atlantic
and sinking it.
Greenpeace saw this as a potential
environmental disaster,
so they sailed out
and took control of the Spar -
a protest that would make
international news.
In a blaze of bad publicity,
Shell reversed their decision
and instead towed it to shore
to be recycled on land
and put the rest of the Brent field
decommissioning on ice.
17 years later,
the process has restarted,
and Austin Hand, who began his
offshore career building Lima,
is in charge.
Did that kind of act
as a precedent for now
how all the fields and platforms
are decommissioned?
We thought it was a reasonable
and logical thing to do,
to take it out to sea,
2.5 miles down in the Atlantic,
and place it in this kind
of valley on the sea bed.
Er, we didn't do a very good job
of explaining that, so basically,
that resulted in the Oslo-Paris
Convention of 1998, that said,
roughly speaking, "You put them
there, you take them away."
A clean seas policy. OK.
That's what Greenpeace strove for,
and that's what they succeeded
in getting.
There's so much involved in this
that the cost of decommissioning
just must be enormous.
Austin's estimate, Austin's view -
$100 billion.
Of decommissioning... In the UK.
There are those that would say,
"I don't believe you, Austin,
"you've over-stated it."
We'll see who's right in the end.
Because of the clean seas policy,
out in the North Sea,
the Lima engineers now face
a really difficult challenge -
cutting the legs of the jacket
to remove it from the sea bed
in a way that leaves no trace
that it was ever there.
To achieve this,
the jacket legs must be cut off
three metres below the sea bed.
This means the only way
to cut the legs
is to sever them from the inside.
It's a job that demands
a very special type of cutter.
As world expert George Jack
explains, there's no blade,
no flame - just water and grit.
Is it the sea water
that you're using there?
Yeah, we filter sea water
in through our pumps,
take it up to high pressure,
and introduce the abrasive
to it as well.
That's the actual garnet
that we introduce to the water.
That's pretty hard stuff? Yeah...
'Garnet is a dark red,
silicon-based mineral.
Although large crystals
are used in jewellery,
some types possess strong atomic
bonds, which make them very hard,
and ideal as industrial abrasives.
If you don't have that
in your water,
there's not enough, er, friction
to cut through the actual metal. OK.
George is about to demonstrate
to me the power
of cutting with water and garnet.
This is the control room,
where we control the water pressure,
the grit monitor... So, what
pressure are we at, at the moment?
Just now, we're sitting at 6,000 PSI.
OK...
'That's 300-400 times greater
'than your typical
water supply at home.'
So, abrasives on.
Yes, that will put your...
introduce the grit into the system,
and the pressure comes up.
Here we go!
He-he! Look at that!
As soon as it starts coming through,
you'll see the water
coming underneath.
Who-hoah!
Now! Now you can see
it's just gone through!
So, that's 50mm of solid steel,
that's just cut. 50mm, yeah.
Compared to, say, a high-pressure
jet hose that you might get for
washing your car or doing your patio
from the hardware store... Yeah.
..if you tried to do that
with this thing,
you'd do more damage
than good, right? Oh, yeah.
The pressure we can barely read
on one of these gauges -
the first line on that,
it goes up in thousands...
I'm not sure what
kind of cut I'm expecting.
Is it going to be a clean cut?
Will it be quite jagged?
Here we go.
Wow! That's clean. That's a really
straight, clean cut.
Surprising, isn't it?
Bit of the old
Paul Daniels, Debbie McGee -
it's gone right the way through.
Yep!
So, this is not for domestic use.
No.
Not for domestic use, I'm afraid!
The Lima engineers are ready
for the high-pressure water cutter.
With the topside removed,
they're able to lower it down,
right inside the legs.
In theory, if the severance
isn't complete,
the crane could pull
the Stanislav Yudin over.
In practice,
fail-safe mechanisms would prevail.
But an incomplete severance
could still cost millions.
We control it from the topside using
hydraulics and everything. OK.
And it'll cut... do a 360 degrees,
sub-sea,
just three metres below the sea bed.
Before they begin the cutting,
every precaution must be taken.
The system is pressurised
to 6,000lb per square inch.
Any leak or breach could be deadly.
An exclusion zone around the cutter
is strictly enforced.
We've got high-pressure hoses
running across the deck.
If you put your hand up like that...
you're not going to have
anything left.
Calculations estimate
that the 360-degree cut
of each leg should take 75 minutes.
All Mick can do now
is time it and hope.
Once the allotted time
has been given to each leg,
special slings are attached.
So all the slings are...
They're not just something
you get off a shelf.
All the slings are engineered
and designed
and built to the length required.
Now the crane must ballast itself
against an unknown payload.
Up to 300 tonnes of extra weight
in marine life
could have accumulated
over four decades,
making the jacket 1,400 tonnes -
as heavy as seven jumbo jets.
All this makes the calculations for the
stability of the crane more and more difficult,
puts the ballasting power of the
Stanislav Yudin yet further to the test,
and her stability in more jeopardy.
And then the big,
tense moment for everybody...
..because we are now going to start
to lift the jacket.
But there's one thing we can't do -
we can't actually 100% guarantee
they're cut by going
and having a look at them.
You hear the crane driver,
he starts taking the weight
on the crane...
..1,200, 1,400 tonnes,
somewhere in that region.
And if he gets to 1,400 tonnes
and then he starts saying,
"I'm at 1,450 now,"
you're thinking, "I hope this
is going to move shortly."
And your heart's probably
going "thump, thump, thump."
And then, all of a sudden,
it just seems to go, "Ooh!"
And it's a great sight, that,
and it's a great relief.
After the final lift, engineers
work through the night to fasten
Lima safely to the barge upon which
she'll make her final journey.
And that was it,
it was an end of an era
for, not only myself,
but for so many people
that have worked on the Inde field
throughout the last 40 years.
In the dead of night, she leaves
the Inde field behind for ever
and sets off on the 200-mile
journey home to the north-east.
Mick's relationship with Lima
has finally come to an end.
Inde produced for so long,
it brought lots of people work,
and, more than that, lots of great
friends and happy memories.
I think that's what'll stick.
I'm now choking up.
Oh, dear.
I can't believe it.
Excuse me.
But, for Lima, this marks the start
of the next phase of deconstruction.
As dawn breaks over the horizon,
Lima arrives at the mouth
of the River Tyne.
From here, she'll be taken to the famous
Swan Hunter shipyard for demolition.
It's amazing to think something like
Lima, how important that was to us.
We just don't really
consider that at all, really.
It's delivering all that gas to our homes,
keeping us warm, cooking our food...
Well, the Inde field
actually produced enough gas
in its lifetime to power the UK
for a year and a half.
Just in one gas field? Yeah.
At the Swan Hunter shipyard,
they must wait for the tide
to be just the right height,
so the barge is level with the quay.
Only then can the painstaking
process of sliding
over 2,000 tonnes of steel
off the barge on to land begin.
You don't see one of them
come over every day, do you?
Four remotely controlled bogies,
with a total of 56 axles,
each capable of supporting
36 tonnes of weight...
Fantastic.
..manoeuvre Lima into her
final resting place.
Now the next chapter in her story
is about to begin.
Ivan Rayne is Geordie born and bred,
and is another person
whose relationship with Lima
and her sister platforms goes back
to their construction in the 1970s.
I bet you didn't have to wear all this
kind of stuff back in the '70s, did you?
Yeah, we did,
but once you got offshore,
if you ever mentioned
the word "safety,"
you were on the next
helicopter home again.
He, too, has come a complete circle.
He's now here to oversee the
demolition and recycling of Lima.
All these pipes and valves and the
kind of meat, everything we can see,
it's all dedicated to getting
that gas up and out of here.
The main function of this platform
is to gather gas from the seabed,
and the gas would be brought up
through six pipes,
brought into this system here,
and then redirected to another
complex, where it is collected
and then it's sent to
the UK mainland for refining.
Then it gets redistributed
throughout the UK,
then it comes into your house
and that's what you use
for cooking your roast beef
on a Sunday.
For Veolia's recycling team
in charge of the demolition,
this is no ordinary take-down job.
So, this has been out
in the North Sea for 40 years.
Where do you start in taking it
all apart and recycling it?
The helideck will be cut off
and pulled over,
then we'll start dismantling it,
section by section.
Once that's flattened,
they'll start cutting it up into
very manageable pieces,
and the smaller the pieces,
the better the value they get for
recycling for transport off the site.
All right,
so now we're talking money.
Typically, what are we looking at
for recycling this whole platform?
You could be looking at anything
from £180-£200,000 scrap value.
After 40 years of service,
providing gas to millions of people,
and jobs and even a home
to hundreds of North Sea Tigers,
Lima is finally about to be brought
to her knees.
First, her infrastructure
is weakened by strategic cuts.
Next, it's time for the excavators
to really get to work.
Steel wires are attached
to the helideck
and the machines go into reverse.
This red accommodation module
is next for demolition.
Its fixings to Lima's frame
have been severed,
and the excavators are standing by.
'Mick Cubitt spent four years
living and working
'on Lima
as an electrical engineer.
'It's almost 19 years to the day
since she last saw her.'
That is incredible.
It's like a bomb...
A bomb has hit the place.
In fact,
it's bordering on unrecognisable.
I don't want to pull any more
emotional punches on you,
but I think that is
your old bedroom,
that red tin shack over that.
I'm afraid so. I spent several... in
effect, the equivalent to two years' worth.
So... Four years, half on,
half off. That's right.
Some 700 nights spent
in that little tin box.
We're about to walk into
your accommodation block,
this is home sweet home. Home sweet
home looks fairly devastating to me.
It's really had the insides
ripped out of it.
So this was the living area, was it?
This is where you passed the time?
Well, prior to the introduction
of satellite television,
we used to show films that were
hired in by the company.
Like your own little Blockbuster!
Yes!
So, Mick, this must have been pretty
cramped. How many people lived in here?
This was accommodation for eight
people, two lots of bunks.
Um, the shower for all four
was in here.
That's the shower tray,
with a wash basin just here.
Shower, wash basin.
That was your emergency exit.
So, it's the middle of the night,
you're asleep in your comfortable
abode and there's an emergency alarm.
The worst-case scenario.
What's the order of service?
Three offs.
The three offs being block off,
we would block in all the wells, stop
the gas coming onto the platform.
You would then vent off. What's
the third off? You just BLEEP off!
Follow me. OK.
Quickly, Mick,
it's an emergency situation!
For Mick's Lima colleagues,
reunited in Lowestoft for the first
time in over 20 years, all that's
left are photos and shared memories
of their incredible offshore lives.
Is this you? That is me on Lima.
How many times would you have been
offshore at that stage, do you reckon?
Probably not many. We used to fish,
didn't we, Tony?
There is some entertainment to
be had. Made our own entertainment.
What was the food supplies like,
did you eat well?
Ate very well. You would have a
choice of a fillet steak, a bit of fish.
That's a decent spread, isn't it?
It is indeed. Christmas crackers.
Explosive devices offshore!
LAUGHTER
If you had a good chef, you had a good
platform, and you'd a productive platform.
One thing I really take away
from this whole process
is it isn't just the hardware, it
isn't just the steel and everything.
It's the family. It's the family of all
the people who've built it, worked on it.
How does it feel now that that particular
field and Lima platform is not there any more?
Does it kind of sit with you,
does it rest with you, or...?
When you finish, you think, "That's
40 years of my life. Now gone."
You just realise how old
you're bloody getting!
Back at the Swan Hunter shipyard,
another relic of the glory days
of the North Sea has been uncovered,
a stark reminder of just how
treacherous it can be.
This looks like a horror story, but
I believe it was just a helideck,
when they removed it,
it smashed into the front.
But this is your survival raft. Yes, this was the
Brucker capsule, as it was known, on the platform.
Awful thing to steer, being circular,
and an awful thing to ride in.
Were you the captain?
I've done the coxon's training on here, and I've
been to see with guys who are happily throwing up,
and it is not the best place to be,
even with a dozen guys in,
when you've got a couple of them
throwing up into their hard hat.
I'm hoping that years of training
means that my Lima veterans
have grown stronger stomachs,
because I'm about to get my first
taste of the Brucker pod experience.
This is exactly the kind of one
you had up on Lima, is it?
Absolutely. Yes, identical.
Identical.
Luxurious, was it?
No! That's how we became friends!
THEY LAUGH
Pods like these have
safely evacuated
more than 2,000 people in over
60 incidents around the world
since Lima was built.
How long is it since you guys
have been in one of these?
For me, it would have been 1978,
in this particular type.
I've been given the job
of releasing the capsule,
and it's fair to say that the speed of
the response takes me by surprise.
Right, we're off.
They were designed for
the Gulf of Mexico,
but the bobbing doughnut was no match for the
waves and currents of an undulating North Sea.
The survival pods, still vital
for an industry which
has claimed hundreds of lives,
are now usually boat-shaped.
I'm being shown at the ropes
by Nick Goldspink,
who's been teaching North Sea Tigers
how to navigate these pods
since 1989.
I mean, we're moving around like
a boat but, still, this round shape
seems like a very odd design
for a boat to me.
Yeah, it's partly to do with strength
and it's partly to do with
ease of operation.
The traditional style of lifeboat has
got a cable at the front and the back,
and there's a chance
that that can hang up.
There is no chance and no possibility
of that with this shape of boat.
Obviously, there is a compromise
to the shape,
and that is that they do
bob around like a cork.
Round boat, though,
how do you even steer this?
Yeah, well, that is more difficult
than a traditional lifeboat shape,
but the advantage to that
is they are very manoeuvrable.
But she's steered, basically,
from the tiller, here,
which again,
is unusual in a lifeboat,
to steer a boat from the front.
If you were to evacuate,
how long would you be able
to survive in a craft like this?
A fairly long while would
be the answer to that.
I mean, there's enough water
and food for a week.
I would not want to be stuck in here
for a week with 27 other people.
You'd get to know them fairly well
fairly quickly!
You would become quite an intimate,
an intimate team.
So, how was that, gents?
Bring back a few memories? Yes.
I have to say, 20 years on, I never
thought I'd be back in one of them!
Back on Tyneside, there's
nothing shipshaped about Lima,
which is being slowly cut down
girder by girder,
making it no longer possible to trace
the pathway that gas would have taken,
snaking through miles of Lima's pipework
from under the sea to our kitchen hobs.
So, to solve the mystery
of how she worked,
I'm going to see an offshore
platform in action
and trace the fossil fuel route.
I'm bit anxious, because I've never
been on a helicopter before.
Thanks to gas and oil, Aberdeen
heliport is Europe's busiest,
ferrying almost half a million
passengers offshore every year.
Across the North Sea, more than
100 lives have been lost
since air transfers began,
which is why every possible
safety technique is used.
I'm terrified, truth be known.
Absolutely terrified.
In the event
of the helicopter ditching,
this suit will increase my survival
time in the freezing North Sea
from just minutes
to about seven hours,
but I hope I don't have
to put it to the test.
After an hour of seeing nothing
but sea, a platform comes into view.
100 miles offshore from Aberdeen,
in the northern North Sea,
this is Nelson,
which produces both gas and oil.
The fossil fuel's pathway on Nelson
is very similar to Lima's
gas pathway,
so I'm going to track the route
from under the sea to our homes
and explore how current
technology works.
While Lima had six wells,
Nelson has drilled 28.
Nelson's manager, Nick Macleod,
is going to show me the drill floor.
Wow!
Pretty impressive drills there!
That is impressive.
Our wells here can go down
as far as 20,000 feet.
20,000 feet? Yeah.
And eventually we get down to what's
called the pay zone, which...
Pay zone? Yeah, the pay zone -
that's where the money is!
Yeah, yeah. That's where the oil
and gas is. OK, what happens then?
It all spurts up, doesn't it?
And everyone cheers!
In the old days.
Hopefully not these days!
The first crucial stage for the fuel
that emerges is the well bay.
Everything is moving about
and juddering. It's really noisy.
Absolutely unbelievable.
It's unbelievable to consider that
they've made this size of machine.
It is even more incredible
when you realise that we're
100 miles off the coast.
Production engineer Murdo MacDonald
is here to explain the first step
of the fossil fuel's pathway...
Oh! There's not a lot
of room in here.
..which involves something known
in the trade as a Christmas tree.
Why is it actually called
a Christmas tree?
Maybe it's because they look like
they've got branches coming off.
You've got all the gauges
hanging off...
You've got quite an imagination
if you...
Aye, you've got quite a bit...
You have to with two weeks offshore!
When a well's drilled,
the raw fuel comes up the conductors
into the well bay.
On Lima, this was gas.
On Nelson, it's gas and oil.
Here, the Christmas trees, large
assemblies of valves and gauges,
help control the flow of oil and gas
entering the platform.
I'm ready for my first offshore job.
Five turn!
Oh, one... two... three... four...
Five turns!
What have I done? You've just
closed the choke in about 5%.
Just closed the choke in 5%?
Which has restricted the oil
flow coming up...? Absolutely.
Stage two of the pathway
is all about separating
what emerges from the well
into its constituent parts.
It's like science fiction film.
When a well is drilled, oil comes up
the conductors into the well bay,
but it's not pure oil.
It's a mixture of oil,
gas and water.
In order to extract the valuable oil
and collect the gas,
the whole mixture is sent
to one of the most important devices
on the platform - the separator.
I've made a model
of Nelson's separator,
to explain to Rob how it works.
It's bafflingly simple.
We have here a bucket,
which to the casual observer
appears to be a generic brand of
cola mixed with vegetable oil,
which is actually exactly the same
as oil, water and gas, all right?
That's from the bottom of the sea.
We've got a pump but, normally, that's got
enough pressure to be forcing itself up.
Exactly. That would be pushed up
under its own steam.
So, what you do,
you separate them out.
The gas will naturally
float off to the top. Yes.
Lighter than both of them. So that will
normally be tapped and off into wherever else...
Exactly, that'll be tapped
and processed, yeah.
Water is heavier than oil.
So, this weir is very important,
because the oil floats on the water.
OK, you see that easily here.
So, the brown stuff is the water
and the creamy stuff is your oil?
Exactly. So, because the oil
is floating on the water,
it flows over the top of this weir,
creating this secondary chamber
here, which is pretty much all oil.
So, coming out of here
you get pure oil,
coming out the bottom of this
section you get flat cola -
or water. Yeah.
Coming out the top, gas. Gas.
This separation stage of the fossil
fuel's pathway is vitally important,
because it tells the energy company
how much gas and oil they are producing.
To do this, every day, each well
is taken out of production
and diverted into
the test separator.
Tom, pleased to meet you.
You too. How's it going?
In the control room, Pete O'Connor
is monitoring results.
So, that's the production
valve there -
the diverter valve, which is open.
That's the test one, which is shut.
So, by putting it into
the test separator,
it lets us know how
the well's performing,
how much oil it's producing,
how much water
and how much gas it's producing.
All our wells, now,
are starting to water out.
They're all over 80% water.
And that didn't used to be the case?
No. No, they all gradually, they
gradually decline in oil production.
So, the test separator
is actually testing the mix
of oil, to gas, to water?
For each individual well. Yeah.
We have a spot rate there,
which, at the moment,
can tell you we're doing
19,357 barrels, near enough,
today, at the moment. Wow!
At that rate, Nelson produces oil
worth around £1.5 million a day.
Not a bad return.
The third and final stage
of the fossil fuel's pathway
is exporting it.
Water is cleaned
and pumped overboard.
Oil is cleaned and then pumped
down the export pipeline to shore,
but it's not all over for the gas.
Some is exported to gas terminals.
Excess is burnt off
on the iconic flare stack.
But most of it is diverted
to something known as the gas lift
to do an important job.
Because of the weight of the ocean
on this trapped reservoir
of hydrocarbons,
it's all under pressure...
Which is kind of like this.
Ha-ha-ha!
So, the moment the drill pierces
it, BOOM! Wow, you've got oil.
The oil comes out. Now, obviously,
quite soon it loses pressure.
So, once they've been
tapping the oil off...
So, it becomes, like, the field
becomes flat? Yes, exactly.
It becomes flat,
it becomes devoid of pressure.
Yeah. So, what you do,
instead of pumping it up... Yeah.
..you push gas down
into the reservoir,
which makes the oil light
because it's got gas in it,
which then sends it back up.
You basically make the world's
biggest SodaStream! Yeah!
The gas collected from the separator
is compressed, repressurised
and then reinjected back down
the well via the Christmas tree,
forcing more precious oil up.
The force required
to do this is huge.
On the platform, Murdo shows me
where they get it from.
It's a gas compressor,
which is essentially a jet engine,
and it's one of the noisiest things
I've ever experienced.
SHOUTING: The engine drives
the power turbine,
that drives the gas compressor.
The gas compressor takes the pressure
from five bar in the separator,
takes it all the way to 147 bar.
'That's 147 times
atmospheric pressure.'
That 147 bar is then used
in the header to reinject
back down the wells and lift
the oil back up again.
They've a powerful blow,
those jet engines.
I'd say it's quite a blow, all right.
But while Nelson's conductors
are still full of North Sea gas,
Lima's conductors now lie severed
from the rest of the platform
on the quayside at the
Swan Hunter yard near Newcastle.
Demolishing them
is going to be a feat in itself.
Because of the way the wells
are drilled and constructed,
they end up with pipes
within pipes, within pipes,
all sealed with thick
layers of cement.
Turning this into small pieces
of scrap metal requires
a process known as bombing.
First, the gas axe is used
to cut along both sides
of the long steel conductor.
Then, to get at the inner pipes,
the excavator steps in.
Once it's made short work
of the concrete,
the inner steel pipes are revealed,
and the process starts over again.
With over a third of a kilometre
of conductors to scrap,
it's a lengthy process.
Meanwhile, on the other side
of the yard, only Lima's legs -
or jacket as it's known -
still remain.
Built from over 1,000 tonnes
of high grade steel,
it must be broken up into
small chunks to be recycled.
The first stage is to bring
the structure to its knees.
Strategic cuts must be made
so the legs collapse neatly.
But it's a dangerous job.
As soon as a cut is made,
the platform is weakened
and may fall at any time.
Are you guys responsible for felling
the legs? Yes, we are.
I wouldn't like to be the guy
who does the final cut.
Who's in charge of that?
Whoever wants to do it.
The backside gets a bit twitchy
when the final cut's made.
I can well understand.
I think if it was me,
the moment the axe is finished,
I would be turning and running.
Do you actually...?
Oh, no. There's no need to run.
In a carefully controlled
and calculated procedure,
towlines attached to the top of the
jacket will be used to pull it over.
This is the first time this method
has been attempted
anywhere in the world.
We attach two ropes either
side of the jacket
and a safety rope to the very back
of the jacket,
just to stop the back legs
toppling the wrong way.
The engineers have put down a bed of
earth for the legs to collapse onto,
to cushion the impact.
They've got two lines, haven't they?
Yeah, two pulling lines.
These guys will take
the tension up on the wire.
Just give it a little tug.
It's quite exciting,
just the anticipation of it.
Before it comes down.
Everything clear? RADIO: 'Clear.'
Don't let anything in now, cos
we're about ready. 'All clear, Mick.'
If the 30-metre-high back legs were
to fall in the wrong direction,
they could land on a factory
behind the shipyard.
Excited to see these come down?
I love it. Brilliant.
Well done. Brilliant.
That was awesome. Congratulations.
And that's the way to do it.
RADIO: 'Perfect, Ned.'
The demolition of this jacket
for recycling is the final act
in the scrapping
of the Lima platform.
'Although veteran Lima engineer
Austin Hand
'is working in decommissioning,
'he has not seen Lima - the platform
he cut his teeth on - for 20 years.'
There she is now.
Wow.
I'm so used to building things,
so to see it dismantled
and in pieces is just...
You're probably quite used to it
in this condition, in a sense.
I can still see the module, yeah.
Just on a different curve
of its life. Yeah.
That really reminds me
of going on and off
that barge for months.
Getting it completed,
just walking over the gangplank
and working 12 or 14 hour days,
every day.
But it was fun and exciting. I'll
bet. Yeah. That gives me a buzz.
We were the young pioneers
in those days.
We were the ones bringing oil and gas
to the UK. It was exciting.
Good memories.
So, we've seen, Austin,
as this process has unfolded,
the huge machine of Lima
being reduced to small piles
of steel rubble.
I was surprised to see
so much timber on show.
Can you tell me about this?
They used to say in my day that
the rigs were made of wood
and men were made of steel,
but that's not actually true.
What this was is we covered the main
steel deck with this timber
so that when you were lifting
stuff off the supply boats
and landing it on the platform,
you had some absorption material
to avoid damaging the deck
or even the container.
So, all this timber here
was to provide you
with a huge cushioned area
to protect the whole thing.
Like a massive chopping board,
in way. Absolutely, yeah.
This steel tubing once formed the
jacket that supported the topside.
It's now been broken up
into sections, ready to be recycled.
'But to the expert eye,
even these fragments reveal
'the challenges of these early
pioneering designs.'
In the '70s, sometimes the quality
wasn't that great.
This is a good example here.
This is a very tough angle for
a welder to get in at these points.
Yeah, you get right down in there.
Exactly. So, in an ideal world,
that brace would have been
at less of an angle.
Very often, the designers just wanted
it to be structurally robust.
Then, when it arrived for us to deal
with in the construction yard,
you think,
"Wow, why did they do that?"
Yes, so on paper, mathematically,
it makes perfect sense.
Exactly, but sometimes
it wasn't constructible.
But again,
this was a learning process.
We'd feed that back in
to the next jacket and say,
"Can we do this slightly
differently?"
That's how we evolved the industry,
getting better and better
and ensuring these wells
were sound and solid.
All these things had to be
considered, even with a relatively
simple structure like a jacket.
For the final time, the excavators
pull on Lima's infrastructure
to bring down her last storey.
The legs are going to go.
There she goes.
It's very sad to see that, something
that you built when you were
a 25-year-old, and you're pulling it
to bits when you're a 59-year-old.
It just shows you, time moves on.
Nothing stands still.
Lima is now unrecognisable,
just heaps of rubble and thousands
of tonnes of scrap steel.
Amazingly, some 99% of this
will be recycled.
The wood from the decks is pulped
and made into paper.
Even the 300 tonnes of algae
that collected on the legs
will be recycled for compost.
But most lucrative is the steel.
Once the various grades
have been separated out,
it's then smelted and made into
new girders and pipes.
Fittingly, just half a mile
down the road,
steel from the smelted remains
of machines like Lima
are being used to build this...
..a brand-new 21st-century platform.
To put it in perspective, whereas
Lima weighed a few hundred tonnes,
this weighs in at a whopping
12,000 tonnes.
Platforms like this are giving
the North Sea a new lease of life.
But Lima and its gas field
are now just a memory.
Removing it cost more
than £200 million, took two years
and over a million staff hours
to recycle 2,000 tonnes of steel,
311 tonnes of algae,
find homes for two generators
and scrap two toilets
and 12 well-worn bunks.
Ironically, some of
the North Sea Tigers who pioneered
offshore platform installation
are now involved
in the biggest new North Sea
industry -
taking them back down again.