Inside Mighty Machines (2019–…): Season 1, Episode 4 - Deep Sea Oil Rig - full transcript

For over 40 years, the Brent Delta oil rig stood tall in the North Sea, extracting oil and gas from beneath one of the roughest seas on the planet. Now this extraordinary machine has reached the end of its life and has been towed ...

Chad zdenek:
A giant deep-sea oil rig

In the middle of the north sea,

Built to withstand
wild and violent weather

And drill deeper
than ever before...

...To pump
two billion barrels of oil.

Now this extraordinary machine
has reached the end of its life.

Now here's the inner
workings of an oil rig.

Salvage teams are ready
to take it apart...

Oh, yeah, it's going.
It's going.

[laughs]

...And sell what they can



To be melted down and recycled.

Give me the honors.

As they strip it back,

I'll get up close
and hands on...

It's huge.

...To uncover
the five engineering innovations

That made it
a giant of its time.

I'm chad zdenek.

I spent seven years building
rocket engines for nasa.

Now I'm taking things apart,

Breaking down giants
of engineering piece by piece

So I can discover what made them
legends of their time.



Hartlepool, on the northeast
coast of England,



The final resting place

Of what was once the world's
deepest drilling oil rig.

Now, we've all seen oil rigs
out at sea on television before,

But few of us
have ever gotten this close,

And I can't believe
the sheer size of this thing

And can't wait to get inside.

It's 40 stories tall,

Covers 60,000 square feet,

And weighs nearly 26,000 tons.

This huge platform stands on
the remains of three giant legs

That once held it
above the water

And stretched 500 feet
to the seafloor below.

From there,
it extracted oil and gas

Almost 9,000 feet deep
and pumped it to the mainland.

Now, after 40 years,

The brent delta rig's
working life is over.

It's been towed ashore,

Where it will be worth
millions of dollars

As recycled metal

Once it's been cut into pieces
and melted down.

But this thing was built
to be indestructible,

So taking it apart
won't be easy.

One of the reasons
I'm so excited to join this team

Is that they're
attempting something

That's never been done before...

To deconstruct an oil rig
of this size on land.

The engineers are literally
having to figure it out

As they go along.

The rig is massive,

But its construction
is surprisingly intricate.

Duncan manning: It was
an engineering marvel

To put these platforms in place
in the northern north sea

And extract oil and gas.

Reversing that process now
and removing platforms

That were never designed
to be removed...

Decommissioning wasn't
a design feature...

Presents a real engineering
challenge for engineers today.

Chad: So, how much are
you guys hoping to recycle?

Manning: What we're
trying to aim for is,

Is over 97 percent
of this platform

Will be, will be recycled.

Chad: That would net them
around $5 million as salvage,

Cash that would help
take some of the sting

Out of the huge cost of safely
decommissioning this thing.

But getting their money out
will be hard work.

Over the next nine months,

I'm going to help
the demolition team

Tear the rig apart
as they try to do it.

While they salvage what they can
to sell for recycling,

I'm going to unlock
the five engineering secrets

That made this rig
a record breaker...

The incredible drilling system

That bored
through the ocean floor,

Then sent oil and natural gas
9,000 feet to the surface;

The tanks that separated the
precious oil from water and gas;

The huge safety valve

That burned off dangerous gas
in a 100-foot flame;

The supercharged
jet-engine-powered generators

That provided
nonstop electricity

Over 100 miles from land;

And the blast-proof
accommodation block

Built to protect crew
from lethal explosions

And some of the worst storms
on the planet.

I really want to get
to the drill derrick,

But it's right
at the heart of the rig,

And we can't just cut it down
straightaway.

The whole structure
is carefully balanced

On what remains
of its three legs.

Take too much weight
from the wrong place,

And the whole thing
could topple over,

So we have to cut
the structure into sections

And pull them out one by one,

Kind of like
a giant game of jenga.

Alan graham: Everything
on the outside of the rig

Was cantilevered,

So we've had to dismantle
the rig into itself.

And we need to keep
the center of the gravity.

Chad: And then when we'd have,
like, a big accommodation block

Coming off the side,
we've got to make sure

There's still enough weight
to keep this thing centered.

Graham:
That's what it's all about.



Chad: With that in mind,

The demolition team
is going to start here,

The rig's
power generation module.

It weighs 500,000 pounds

And will be worth
tens of thousands of dollars

As scrap metal.

It's also home to an ingenious
engineering innovation

Which I want to uncover.

The brent delta needed as much
electricity as 10,000 homes

Every single day,

So engineers had to find a way
to deliver all that juice.

The problem
was shell's brent delta

Was standing all alone
in the wild north sea,

100 miles from land and
the nearest electrical supply.

The solution was to get the rig

To create
its own electrical power,

So engineers installed
three huge generators

Powered by three
very special engines.

Together they created
enough electricity

To run an entire town.

They powered
the drilling system,

The oil pumps,
the processing units,

And everything necessary
to support a crew of 160 men.

The genius of the system

Was that it made the rig
energy self-sufficient.

To find out how,
I've got to get inside,

Using my trusty flame cutter,
somehow.

I've got my burning gear.
I'm ready to cut some metal.

Now it's time to say goodbye
to the power generation module.

We're starting with the roof.

It's connected by chains
to a crane to support it

So we can cut through the beams

That attach it
to the rest of the structure.

I'm making the final cut,

Which will leave it
dangling from the crane.

[thud]

Whoa! There it is.

It dropped a good inch.

All the weight's
on the crane now.

Still hear it creaking.

Now we can lift it clear.

Now, there's
something satisfying

About making a final cut
on a 22-ton roof

And seeing it lift off.



As the roof and walls
are removed,

I'm hoping to see
the three engines inside.

It turns out, I'm too late.

They're so valuable,
they've already been salvaged

And put back into service
on another rig.

All that remains is the housing,

Which our crane is dismantling

To reveal these
three open exhaust shafts.

They're all that's left
of the genius brain wave

That made the brent delta
energy self-sufficient.

It so happens that natural gas

Is a normal by-product
of pumping oil.

It gets brought to the surface
with the oil,

Where it's separated away

And, for years,
was burned off as waste.

But in the 1990s, brent
engineers realized natural gas

Was the power source
they needed,

If they could figure out
a way to harness it.

All the engineers needed was
an engine that could run on it,

Compact enough
to fit on the oil rig,

But powerful enough to keep
the entire platform running,

And for that,
they looked to the skies.

The electric lightning
was a cold war fighter jet

Used by air forces
around the world

In the fifties and sixties.

It had two avon jet engines,

Which provided so much thrust,

The lightning could fly
at twice the speed of sound.

Pilots described flying in it

Like being saddled
to a skyrocket.

I've come to this overhaul
facility in scotland

To see one up close.

The basic design
is classic jet engine.

These blades
will suck air in here,

And that air is compressed
in this section.

The compressed air
is mixed with aviation fuel

And then ignited
inside the combustion chamber.

Hot exhaust gas
will blast out of here

At 1,200 degrees fahrenheit,
creating 26,000 horsepower.

The brent delta engineers'
ingenious solution

Was to install
three of these jet engines

And use them
to run the rig's generators.

All they had to do
was modify the engines

To run on gas
instead of jet fuel.

Then they directed that blast of
hot exhaust gas into a turbine

Connected to the generator,

And that way produce
the 36 megawatts of power

The rig needed every day.



Since then, the avon engine has
become an oil industry standard.

700 are still in use
on oil rigs today,

And many get sent to this
facility to be overhauled.

I'm helping install new
compressor blades on this one

Before it's put back
into service.

So, we're working
on reassembling

This overhauled engine,

And right now
it's in the vertical position,

And the inlet's at the bottom.

So, essentially, the air
would come up through here,

And it goes through
each of these stages

Of this giant
compressor section.

It's going to be compressed
more and more

Until at the top,
it's going to be mixed with fuel

And then ignited
in the combustion chamber.

Believe it or not,
this engine is 30 years old.

It's already had
150,000 hours of service,

And after this major overhaul
that we're giving it,

It's going to be good
for another 30,000 hours.

Considering that this engine
has been out in the north sea

On an oil rig
for all these years

And it looks this good
and still continues to work,

It speaks volumes to the design
and the engineering

That's gone into it.

20 years ago, this deck roared
with the sound of those engines.

Today, it's the sound
of flame cutters.

We're slicing
through the final uprights

So what's left
of the power module

Can be pulled to the ground
in one giant chunk.

That will take brute force.

Pulling down
a 400-ton block of metal

Can't be done
with normal ropes and cables.

Now, these are some serious
heavy wire rope.

It's about two inches thick,
and I can barely lift it up.

But the key is that we've got it
wrapped around the top

And then down here
shackled together,

And we've got
the excavator behind me.

It's going to come up

And literally
just grab these two ropes,

Start pulling,
and then it's coming down.



Okay, time to stand back.

Oh, yeah.
It's going. It's going.

The mighty brent delta oil rig
has reached the end of its life.

Now, in a world's first,

All 26,000 tons of it
is being taken apart on land.

The power generation module,

Which provided electricity
to the rig,

Is the first section
to come crashing down.

[laughs]

Oh, man!

And now the hartlepool skyline
is now changed.

This rig is now on its way
to being completely recycled.

But in 1973,

The rig was the solution
to an economic disaster.

Announcer: Anwar sadat
takes up leadership

Of the arab crusade
against israel,

And in 1973,
he orders egypt to attack.

Chad: When america supported
israel in the yom kippur war

Against egypt, syria,
and other arab states,

The arab coalition responded

By drastically cutting
the flow of oil.

Within months, american
gas pumps actually ran dry.

A new 55-mile-an-hour
speed limit

Was introduced to save fuel.

There were even calls
for rationing.

Western powers
needed oil urgently.

As energy independence became
a political priority,

Countries began looking for oil
a lot closer to home.

The united states
ramped up exploration

In the gulf of mexico.

Meanwhile, britain discovered
its salvation in the north sea.

Announcer: Liquid gold...
Call it what you like.

Britain now has oil, billions
and billions of barrels of it,

And it's been quietly lapping
at the doorstep all the time.

It has been estimated
that three percent

Of the world's oil reserves
lie beneath the north sea.

All these years,
britain has been sitting

Beside a fabulous
industrial treasure trove.

Great britain
has struck it rich.

Chad: In 1974, shell oil
commissioned the construction

Of four massive rigs
to cash in on the bonanza.

They wasted no time.

By the end of 1978, all four...

Alpha, bravo, charlie,
and delta...

Were up and running
in the brent oilfield.

From there in the north sea,

The brent delta helped
the united kingdom cash in

On more than two billion barrels
of oil over its lifetime.

Today there's still money
to be made from the rig.

Prices fluctuate,
but melted down,

The scrap is worth
around $200 a ton.

So, the power generation module

Has hit the deck
in dramatic fashion,

And this is
all that's left behind.

All that's left to do now
is cut up this monster module

And get it
to the recycling yard.

So, it's another chance for me
to melt some metal.

To do that, we use cutters

That use oxy propane blowtorches

That burn at over
5,000 degrees fahrenheit.



It takes me about five minutes

To cut through this giant pipe,

Which is about two inches thick.

Wow.
[laughs]

Now, that's how
you cut some steel.

This 250-ton power unit
could be worth up to 50 grand.

The steel will be melted down
and turned into new sheet metal.

There's enough
on the brent delta

To make
200,000 washing machines,

But it could end up
as anything...

A railroad car,
a construction girder,

Even the hood of your next car.

Every cent
they make on recycling

Will help offset the steep cost
of decommissioning this rig.

Why is it so expensive?

Because just getting
this platform ashore

Was an engineering miracle
in itself.

It's taken more than a decade
to get this far.

In 2006,
engineers began planning

Just how to carry the 26,000-ton
brent delta to land,

Where it could be
safely dismantled.

It was a daunting prospect.

They knew there was
only one ship in the world

Big enough to event attempt
to lift it.

[horn blows]

And this is it,
the pioneering spirit,

The largest construction vessel
on the seas,

As long as six 747s.

Its job was to lift and carry

The enormous weight
of the rig platform.

If engineers could achieve that,

This would be the biggest lift
ever completed at sea.

After years of preparation
and billions of dollars,

In April 2017,

The record-breaking attempt
took just ten seconds.



[horn blows]

[laughter]

For now, the three 500-foot legs
have been left in place.

They're still not sure
what to do with them.

The engineers' next problem

Was where to put the massive
26,000-ton oil platform.

Once ashore, its enormous weight

Would simply sink
into the ground,

So the decommissioning engineers
designed and built

A $30-million
specially reinforced quay

To support the rig
when it came ashore.

Even from a technical

Or engineering standpoint,

Just getting it from

The north sea to the dry dock

On land here was a big effort.

Peter stephenson:
Very innovative, yes.

There's been a tremendous amount
of work, research,

And design engineering done
to make sure this went right.

We've built a very big expensive
quay here to take this in

Because it's very heavy.

The load pressures
coming out here

Is 60 ton a square meter,

Whereas most quays
are five ton a square meter,

So it's much heavier

Because all this 25,000 tons
just on three legs.

Chad: Everything about
this project blows my mind.

The engineering
is just incredible.

Everywhere you look,

They're doing something
for the first time,

And they're using
brand-new techniques.

Now, with the power generation
module removed,

I can get to the invention
at the heart of this rig...

The incredible drill derrick.

This is the inside
of the drilling derrick.

It's been partially dismantled,

But when the brent delta
was out at sea,

At its peak,
over 500,000 barrels of oil

Would flow through here
every single day.

The drilling derrick
secured the drill and the pipes

That reached from the surface
to the seabed

And thousands of feet beneath.

The derrick is actually
just one big lifting tower.

This is the lifting hook.

Normally it would be
way up there,

And it was used to lower
the pipes into place,

Where oil crews would
wrestle them into position.

It drilled
to reach oil reservoirs

Almost 9,000 feet beneath
the surface of the earth,

Deeper than any other rig
on the planet.

The controller would sit in here
to run the lift systems.

It's hard to believe now,

But this was the cutting edge
of oil exploration 40 years ago.

And it's still basically
how rigs operate today.



I'm getting on this rig to show
you how to drill for oil.

Drilling deeper than ever

Needed a drill
that was longer than ever.

It was pieced together
in massive sections.

That's where
the 130-foot derrick came in.

It has a big winch
called a top drive

To raise and lower giant lengths
of drill pipe into position

And turn the drill head
thousands of feet below.

Essentially this is the drill
that does all the work

At the bottom of a well.

On the brent delta,

This could bore a hole
up to four miles deep,

And the way it does it,

It has these three conical heads
here which spin,

And the hardened steel tips
will crush the rock

And drill the hole.

All right, so,
we've got the drill bit here.

We're going to stick it
into the well hole,

Drop it down a little bit,

And we've got these slips,
which are just friction slips

That are going to
hold it in place.

Just this drill bit's
about 500 pounds,

And we're up
about 40 feet off the ground,

So we got to make sure

This thing doesn't drop
all the way down.

On the brent delta,

The bit had to be lowered
through 500 feet of water.

But that was nothing compared
to the 8,000 feet of rock

It had to bore through
after that.

With our drill head
held in position,

We can start to attach
the first length of pipe.

So, we've got the guy
way at the top,

And we're sending
the top drive up to him.

He's going to connect up
to the top of a 90-foot section.

We move that into place,

And we're ready to connect it
right down here at the well.

Just like the brent delta,
the winch's top drive

Is controlled by the operator
in the control room.

He lowers the pipe
into position.

So, now we're just going to
tighten this thing up by hand.

Sometimes I feel like I'm going
around and around in circles.

And that's as tight
as I can manage.

Next, it's over
to special hydraulic grips

Called rig tongs.

I managed to exert
around 200 pounds of torque

To turn the pipe,

But these things
have a bit more muscle.

Now, just to put it
into perspective,

These rig tongs have
65,000 foot-pounds of torque.

That's strong enough
to tear a car in half.

The rig tongs clamp
onto each section of drill pipe,

Then twist them together
until they're locked tight.

This is all heavy work,

Which covered workers
in wet mud.

One mistake could cost a finger
or worse.

Even so, the drill teams
worked at high speed,

Like a well-oiled machine.

I can't imagine
matching their pace.

I'm only just ready
for my second piece of pipe.

We're going to grab
another 90-foot section,

Set it on top,

And we're ready to keep
going down and down and down.

You're going to keep
doing that cycle

And make this
as deep as you want.

You can see behind me,
we literally have

Thousands of feet of pipe
just right here.

Once the chain of linked pipes
hit the seabed 500 feet below,

Brent delta workers
would fire up the drill.

When we're down into the rock,

This thing will spin
at about 150 rpm,

Depending on
what we're drilling through,

And we can do either
two feet an hour

Or 200 feet an hour,
depending on the type of rock.

Oil is held under enormous
pressure within porous rock.

By drilling a hole,
you release that pressure

And the oil rushes
into the bore hole.

External casing pipes
around the drill bit

Carry the oil
all the way up to the surface.



And that's how
to unlock black gold

From bedrock
beneath the ocean floor.

Once the oil has been processed
at the surface,

It was stored in brent delta's
massive hollow legs.

Then it was pumped
to the mainland

Through a pipeline
on the seabed.

Efficiency is key
to the rig's business.

As expensive
as they are to operate,

They need the oil
to be constantly flowing,

But drilling through the seabed
produces a lot of debris.

Clogs were a constant problem.

The answer... pump mud and water
down the drill pipe

To flush out the debris
and bring it to the surface.

Here, it's filtered out,

And the cleaned mud
and water mixture

Circulated
back down the drill pipe.

The system meant that the drill
could cut continuously.

It also solved another problem.

It prevented the drill head
from overheating.

You can picture if you're
drilling into a wall

Or a piece of metal
or even masonry,

The tip of your bit's
going to get really hot.

Well, you can only imagine
what it's going to be

When you're going through
thousands of feet of rock.

And this water-based mud mixture
will act as a lubricant.

With enough pipes
connected together,

Brent delta's drill
could reach almost any depth,

And with the circulating mud

Removing debris
to keep the drill cool,

It could continue
drilling even deeper.

After 40 years
of that round-the-clock service,

This drill derrick
will soon come tumbling down,

But not just yet.

To keep the rig balanced,
they have to pull down

All the other modules
that surround the derrick first.

One of the biggest is this one,
the accommodation block.

It provided workers
with a place to live,

Safe from extreme
north sea weather

And the risk
of deadly explosions.

It's the next innovation
I want to get inside

As I uncover the secrets
of its blast-proof design.

The brent delta's
accommodation block

Was home sweet home to 160 men

Working around-the-clock shifts.

This empty cavern was once
a place of rest and friendship

For over 40 years.

Alistair hope: This is where
they would live, eat, and sleep,

So here you had
a whole bunch of cabins,

And you can just about see
the walls of the cabins here.

There would be two people
to a cabin typically.

There would be a toilet
and a shower over there.

There'd be a desk,
two bunk beds,

And a bunch of your cupboards,
and so forth.

Chad: So, literally, like
this is one wall right here.

Hope: Yep.

Chad: And the other wall
right here,

And you have two people
that were living in the space.

Hope: Yes.

Chad: Pretty tight.

Hope: Yeah, and people would
be out offshore for two weeks.

They developed
tremendous friendships,

And some of the people
worked on the platform

Literally from the beginning
right through to, to the end.

Chad: Recently retired
rig worker lawson petrie

Called the brent delta home
for most of his career.

Lawson petrie: This was always
a very friendly platform.

Sunday roast
was the prime for lunch,

And it was the quiz
on a Sunday night.

This is where everyone
came together...

Deck crew, ops,
maintenance, drilling...

We all came together
for the brent delta quiz.

And that was one
of the simple things

That kept the ethos
of the platform going.

Chad: The accommodation block
was designed

To keep workers safe
from the risk of explosions

Caused by processing

Explosive gas
and flammable oil...

Hazards which could be deadly.

In 1988, 180 miles south
of brent delta,

A huge gas explosion engulfed
a rival rig, piper alpha.

Man: Mayday! Explosion and fire
on the piper...

Chad: 167 workers died,

Many of them while sheltering
in the accommodation block.

It was positioned right above
a unit after a redesign

To process huge quantities
of flammable gas,

With devastating consequences.

Brent delta's accommodation
block was positioned

200 feet away from the areas
processing gas and oil.

And it was reinforced
with eight-millimeter-thick

Stainless corrugated sheets

To protect workers
from fire and explosion.

But now that thick armor

Makes dismantling this section
even harder.

I'm helping the teams take down
all the heavy exterior metal

So it's as light as possible
when it's toppled.



Weeks of work has gone

Into cutting and clearing
the living quarters

To prepare it to be dropped,
all 800,000 pounds of it.

All that's left to do now

Is clear out
this last pile of metal,

And we'll be ready
for the final cuts.

The blast walls
and other components

Have been chopped
into manageable chunks.

To reduce flying debris
when the block is dropped,

We need to throw them
over the side.

All right,
so, where should we start?

Man: Anything off this pile
is light and ready to throw.

Chad: All right. Ready?

1, 2, 3.





Give me the honors.

All right.



All right,
doesn't seem like much,

But we got it down
to 800,000 pounds,

So now we're ready
for the final cuts,

And now we'll pull it down
and drop all the rest.

We positioned our cuts
hoping that the three stories

Will collapse
on top of each other.

I can't wait to see
if it worked.

Not exactly,
but that's the top floor down.

Two more to go.



One final pull
should finish them off.



The accommodation block's
armor plating

Offered priceless protection
to rig workers.

Now, as scrap, it could be
worth up to $100,000

To the demolition team.

With it gone,
there's a clear path

To the tallest structure
on the rig,

The 300-foot flare tower.

This is the invention
that allowed the rig

To extract oil
and natural gas safely

Without blowing itself up.



First, we need to pull it down,
but we have to be careful.

If we get
our calculations wrong,

We could take out
an entire building by mistake.

We're four months
into the complete recycling

Of the brent delta oil rig.

Now it's time to take down
the tallest structure.

Here it is, the flare tower.

This is what gives
an oil platform its iconic look.

At the top, there's a flame

That would have been
up to 60 feet long,

Generating enough heat
that you could feel it

All the way down here.

At sea, you could see this
for miles.

And now I want to find out
more about it.

Even though the rig's generators
were powered by natural gas,

They used only a fraction
of what flowed up to the rig,

And it was all highly flammable.

Store it on board,

And you run the constant risk
of blowing up the rig.

Simply releasing it
into the atmosphere

Was too dangerous.

Engineers needed a way
to keep workers safe

From being blown sky-high,

So they designed a system
that allowed the gas

To flow to a giant pilot light.

They put this at the top
of a high tower

So the gas could burn off
in a huge flame

Without risk to the workers.

Alan lawrie is a 40-year veteran
of the brent delta

And knows how important
the flare tower was.

Alan lawrie:
The flare tower is imperative.

We physically couldn't
operate the platform

Without having the capability
to vent off the gas.

Chad: Yeah.

Lawrie: And that's really
why you've, why it's got

The height that it has,
because of the radiated heat.

Chad: If you had
an event like that,

How big of a flare
would you get off the top?

Lawrie: Quite substantial,
probably in the region

Of 30, maybe 40 meters long,

So about 100 to 120 feet long.

Chad: So, you could feel that
from here?

Lawrie: Oh, most definitely,
most definitely.

You could feel the heat
being generated off of it.

Chad: So, what would happen
if the pilot went out?

Lawrie: We would then
light the flare

Using flare gun cartridges,
almost like a shotgun.

We would fire that cartridge
up into the plume of gas.

[flare gun fires]

We would then get the ignition,
and that would then light,

Light the gas
and light the pilot.

Chad: Climbing up
a 300-foot tower

With a shotgun
slung over my shoulder

To ignite a 100-foot flame

Is a job I'm sorry
I didn't get a shot at.

But at least I get to help
pull the thing down.

It's like felling a tree.

We don't cut all the way
through the base.

Instead, we leave
one section intact

To control
the direction of the fall.

Well, that's the theory, anyway.

In that direction, we have
a high voltage power line.

Over here, we have a building,

And over there,
we have the ocean,

So our sweet spot
is to drop it right here.

The problem is,
it doesn't naturally

Want to come down that way,

So what we had to do
is we had to clock our cuts

At the bottom of those legs
so that as it falls,

It's going to pitch it
in this direction,

And if all goes
according to plan,

It's going to land right here.

Well, fingers crossed.

Once again,
we connect the steel cables.



The excavator
increases the tension.

Man, that's a tight rope.



Oh, there it goes.



Yeah!

[crash]

Right in the sweet spot!
Woo hoo!

Right away,
the demolition team moves in

To start cutting it up

So it can be melted down
and reused for manufacturing.

And actually,
it's not the first time

The rig has been repurposed.

The brent delta extracted
over two billion barrels of oil

In the first 17 years
of its life,

But in 1993,

The vast oil reserve
under the rig began to run dry,

And just when it seemed
the rig's time was up,

It was offered a lifeline

By a brand-new natural gas
refinery built onshore.

Now the brent delta's
biggest waste product

Could become britain's
next source of power.

First, engineers had to
find a way to convert the rig

From oil to natural gas.

Their solution
cost $1.6 billion.

It's the next engineering
innovation I want to uncover,

If I can find it.

Wow! Now, here's the inner
workings of an oil rig.

So, I've been going through
a maze of walkways and tunnels

And totally lost my way.

Man: Okay, so, we're just coming
down here to the separators.

Chad: Are those them
over here?

Man: This is one of them.
This is the big one.

This is the little one here,
the test separator.

And then there's another one,
a big one, just over there.

Chad: This is the innovation
I've been looking for,

The brent delta's
giant separation tanks.

The rig's huge drill may have
struck black gold,

But the stuff
that comes to the surface

Is actually a dirty mixture
of oil, water, and gas.

Imagine a bottle of cola,
all shaken up.

The oil, mud, and gas mixture

Is the soda
that's inside of this bottle.

Now, when I release the top,
that high pressure gas

Is going to want to come out,
like that.

Now, if I leave the cap off
long enough,

All that gas
is going to set off to the top.

That's exactly what's happening
inside these separation tanks.

There, the fizzy oil
and water mixture goes flat

As the gas is drawn off.

Then the remaining oil and water
is separated.

When the oil reserves ran out

And gas became valuable
as a fuel,

Engineers made a simple
but important change.

They supersized the tanks

To draw off gas
in much greater quantities,

And instead of burning it off,
they pumped it ashore.

Walking along these tanks

Really gives you
the scale and size.

It's gotta be 50 feet long.

It's huge.

But recycling these tanks has
thrown up an unexpected problem.

The tanks might not be
glowing in the dark,

But it seems
they could be radioactive.

So, robert,
as I was wandering around,

I couldn't help but notice
the "caution",

"Naturally occurring
radioactive material" sign.

I had no idea that that would
even exist on an oil rig.

Where does it come from?

Robert cullen:
Yeah, so we call it norm,

So, naturally occurring
radioactive material.

And, so when you're producing
oil, water, gas

From the reservoir
down below the seabed,

It's encased in rock,

And some of that rock
comes with it,

So there's bits of sediment.

And between the four
of those natural materials,

It can build up
a level of radioactivity,

So everything has
its own level of radioactivity,

But when you concentrate it
over the 40 years of production,

It can build up to a level
that might contain a risk.

Chad: But they still
have to come out,

So we better
handle them delicately.



The separation tanks
have been removed,

And the next step
is to check for radioactivity,

But first, I got to put
my hazmat suit on.

Not every oil reservoir
held radioactive material,

So not all the tanks
are contaminated.

But if this one shows
any sign of radioactivity,

It can't be recycled.

I never expected to have to use
a geiger counter on this job,

But I need it to tell me
the level of radiation.

Every time a radioactive
particle hits the counter,

It measures
what's called a click.

[beeping]

The natural environment
around here

Is reading
.3 clicks per minute.

That's very safe.

Okay, so, now we've got
our ambient reading,

And I'm going to read it
from inside here,

And as long as it's less
than double, then we're okay.

[beeping]

The reading from the tank

Is the same as the rest
of the environment.

Okay, you can see these readings
are well within the safe limits,

And that means we can start
cutting this thing up

And sending it
to the recycling yard.

Supersizing the separation tanks
allowed the rig to process

Over 500 million cubic feet
of gas every day,

And a brand-new gas pipeline
on the seabed

Connected the rig
to the refinery,

But there was still one more
engineering challenge to solve.

Engineers for shell
could raise natural gas

From beneath the seafloor.

Now they needed a way to send it
to the mainland 116 miles away.

That required a pump
with a lot of power.

Once again, they discovered
that aviation had the answer.

Another jet engine,
this one even bigger

Than the avon they used to power
the electrical generators.

This design of jet engine
was actually used on 747s.

It produces
over 40,000 horsepower.

It was dedicated
to pumping ashore

Over half a billion
cubic feet of natural gas

Every single day.

The 747 engine was deafening,

So it was housed
inside a soundproof enclosure.

Its massive thrust
powered a pump

That sent the natural gas
through a pipeline,

All the way back to the refinery
on the mainland,

Over 100 miles away.

This is part of that huge pipe,
a tube of solid steel,

Almost 40 feet around.

That's now being cut into pieces
like everything else,

Ready to be recycled.

Six months
into the deconstruction,

And all the pipework and tanks

Inside the replacement
processing module

Which contained
the separation tanks

Have been completely ripped out.

As you can see,
the replacement process module

Is almost ready to be dropped.

A lot of work
has gone into removing

Those heavy exterior walls
and lightening the load inside.

When they're taking off
these modules,

Would they ever use the big
crane to help lift it off,

Or was it always
by these straps?

Paul connally: No.

Chad: No. It's too big?

Connally: That's only good
for 45 ton. That's 880, so...

Chad: How heavy is this?

Connally: 880 ton, that's what
we're going to be dropping.

Chad: Wow, geesh!

Yeah, so that's not even going
to even put a dent in it.

Connally: No, no.

Chad: Stand by
for another giant drop.



Wow!



Oh! That's huge!

This chunk of rig will be worth
up to $200,000

As recycled metal,

And there's still more
where that came from.

It will all help offset

The huge cost of safely
decommissioning the rig.

Piece by piece, this enormous
machine is coming down,

And we're getting closer to the
final drop of the whole project,

The 700-ton drill derrick,
the dismantling challenge

That will mark the end
of this amazing deconstruction.

It's taken eight months

To dismantle
the brent delta platform.

It once weighed
almost 26,000 tons.

Less than 10,000 are left.
The rest has been recycled.

The flare tower is gone.

The processing modules,
vanished,

With their separation tanks.

So has the generator
and the accommodation block.

But there's still one amazing
piece of engineering

That remains...
The drilling derrick.

It's been left until last

Because it's the rig's
center of gravity.

Now everything around it
has been removed,

We can finally pull it down.

Graham: We brought the rig
back to its base,

This can go now.
We don't need this now.

We're back to the three legs.

Chad: Now you're
making me nervous.

I feel like I want
to get off this thing.

I don't want to put
too much weight on one side.

I've seen how
the drilling derrick works.

Now I want to see
how it's constructed.

It weighs in at 700 tons,

Designed to support the huge
weight of the drill pipe

And to stand up
to the worst storms

The north sea could throw at it.

Graham: On each side
of the I-beams is more I-beams,

Which makes it extremely strong
and extremely heavy.

When the guys come to cut these,

They'll be cutting them
below the main beam.

We can't cut above that

Because that means we are
leaving half the rig behind,

So that's the lowest beam,

So we need to cut the legs
as low as possible.

Chad: I'm helping the team
on the rig

Make the final cuts
so the tower can drop.

So, what we're doing now
is we're preparing this back leg

By cutting through
the four gussets.

We don't want
to cut through too much

Because we don't want
to compromise this

In this high wind.

We got to wait
till the wind dies down

And then do the final cut.

Everything's been cut
except the front left leg,

And everyone's been evacuated
off the rig

Down to the safe zone
on the ground,

Leaving behind
only the top man burner

Who's going to make
the final cut.

The top man burner cuts the
final section of support away.

Then he goes
deep inside the rig to safety

And gives the all clear.

The excavators
are going to begin to pull.

When they do, that whole derrick
is coming down in one big piece.



The derrick is the last
major component to be removed.

The brent delta
has been reduced to scrap,

Worth up to $5 million
as recycled metal.

We've achieved something

No one has ever
attempted before...

Dismantling a giant offshore
oil rig on land.

The techniques used here
will be applied

To ensure a method for safely
taking apart the other rigs,

Protecting the environment,

And recycling
billions of tons of metal.

It's been an epic feat
of deconstruction,

But the legendary brent delta's
journey is finally over.

What was once the pride

Of britain's north sea
oil exploration

Is now ready
to be sold for scrap.

Big engineering brought
the brent delta into being.

Now big engineering has

Almost completely
recycled it on land,

Setting one final world's first

In this rig's long list
of mighty achievements.