0:00:03 > 0:00:07This is the Indefatigable Lima platform.
0:00:08 > 0:00:10It's the last remaining offshore rig
0:00:10 > 0:00:13in one of Britain's most productive gas fields.
0:00:17 > 0:00:23Made up of 2,500 tonnes of steel and almost 15 miles of pipework,
0:00:23 > 0:00:26it's brought over a million cubic metres of gas up
0:00:26 > 0:00:28from deep below the sea.
0:00:29 > 0:00:32For almost 40 years, it's kept us warm,
0:00:32 > 0:00:36supplying gas to five million homes.
0:00:36 > 0:00:38We were the young pioneers in those days.
0:00:38 > 0:00:40We were the ones bringing oil and gas to the UK.
0:00:40 > 0:00:42It was exciting.
0:00:45 > 0:00:49Now, this giant is about to be demolished.
0:00:51 > 0:00:54It's going to be an immense engineering challenge.
0:00:55 > 0:01:00You just keep watching it and your heart's going thump, thump, thump.
0:01:00 > 0:01:02Diamond-coated wires
0:01:02 > 0:01:04will attack two-inch-thick steel.
0:01:04 > 0:01:08It allows the machine to just keep cutting and slicing.
0:01:14 > 0:01:20Gas axes burning at 3,500 degrees will bring it to its knees.
0:01:24 > 0:01:27It's an emotional time for the men who put her up -
0:01:27 > 0:01:31the North Sea Tigers.
0:01:31 > 0:01:33That's 40 years of my life. Now gone.
0:01:33 > 0:01:36Taking her down
0:01:36 > 0:01:38will require remarkable technical skills,
0:01:38 > 0:01:40and will provide a unique chance
0:01:40 > 0:01:44to see right inside this enormous installation.
0:01:44 > 0:01:46Could we get that hook reset, please?
0:01:51 > 0:01:53This is Engineering Giants.
0:02:00 > 0:02:03Lima was at the heart of the Indefatigable gas field
0:02:03 > 0:02:08which was discovered in the 1960s, 70 miles off the Norfolk coast.
0:02:08 > 0:02:13Now, the gas has run out, and it's being decommissioned.
0:02:13 > 0:02:16The whole project will cost £1.5 billion
0:02:16 > 0:02:20and involve the expertise of more than 1,000 engineers.
0:02:20 > 0:02:22Removing every last trace of Lima
0:02:22 > 0:02:25will take nine months.
0:02:26 > 0:02:29I'm Rob Bell, I'm a mechanical engineer,
0:02:29 > 0:02:31and I've always loved to get my hands on complex machines
0:02:31 > 0:02:33to discover how they work.
0:02:33 > 0:02:37I'm Tom Wrigglesworth - I'm a trained electrical engineer
0:02:37 > 0:02:39with a passion for big machines.
0:02:41 > 0:02:44As Lima makes her last journey, from the North Sea back to British soil,
0:02:44 > 0:02:46we'll be taking you through every critical stage
0:02:46 > 0:02:48of the engineering process.
0:02:50 > 0:02:53And as she's torn apart, we'll uncover the secrets of how
0:02:53 > 0:02:56one of the world's biggest machines works.
0:02:58 > 0:03:02Few people know Lima's secrets as well as Austin Hand.
0:03:02 > 0:03:06He worked on her construction at Lowestoft almost 40 years ago.
0:03:06 > 0:03:10It started in Middlesbrough, where it had already slipped on schedule,
0:03:10 > 0:03:13so Shell decided to bring it down here to finish it off.
0:03:13 > 0:03:17- Right across here?- Just on a barge, moored against the quayside, yeah.
0:03:19 > 0:03:22Austin's come to meet two other Lima veterans -
0:03:22 > 0:03:24Bill Lindsay and Mick Needham.
0:03:24 > 0:03:27They haven't seen each other in over 20 years.
0:03:27 > 0:03:29It's been a long time!
0:03:29 > 0:03:32- How are you doing?- I'd like to say we haven't changed much, but...!
0:03:32 > 0:03:36LAUGHTER I'm doing great, really. Yeah.
0:03:36 > 0:03:38Probably the first time I ever came across you
0:03:38 > 0:03:41- was on Lima.- That's right.
0:03:41 > 0:03:43And you...were the main man!
0:03:43 > 0:03:46For me, what's quite special is that you guys
0:03:46 > 0:03:49were...the pioneers, really,
0:03:49 > 0:03:52of North Sea gas and oil exploration, and getting there,
0:03:52 > 0:03:55- getting the platforms out there. - It's a big learning curve,
0:03:55 > 0:03:58for all of us - we were only young lads.
0:03:58 > 0:04:01I joined Shell in 1971 as a 22-year-old.
0:04:01 > 0:04:03I'd been working power stations, and didn't even know
0:04:03 > 0:04:05- what an offshore platform looked like.- Yeah.
0:04:05 > 0:04:08Six years...five years later, I'm building them.
0:04:08 > 0:04:12In them days, the southern North Sea was quite a family unit.
0:04:12 > 0:04:14We didn't have too many people coming in as, like,
0:04:14 > 0:04:18international - it was mainly local lads and you kind of stuck together.
0:04:18 > 0:04:22- Right.- And I think that's...these days, changed.
0:04:22 > 0:04:26To your friends and family, who weren't necessarily working
0:04:26 > 0:04:28in and around the gas and oil industry, the stories
0:04:28 > 0:04:31you must have been coming home with every week, they must have been,
0:04:31 > 0:04:35- "What?!"- It was awfully difficult for the families, because
0:04:35 > 0:04:38if you're working in a shop or factory, they've got a perception
0:04:38 > 0:04:41of what it looks like, but out there, they had no idea
0:04:41 > 0:04:45- what it was like.- No idea.- My oldest girl was only about four then,
0:04:45 > 0:04:50and I had to bring pictures home of a bed and a table with food on it,
0:04:50 > 0:04:53and she was happy then. But she just thought I was working in the sea.
0:04:53 > 0:04:56Mick Needham's involvement with Lima
0:04:56 > 0:04:59started when she was built.
0:04:59 > 0:05:03My relationship with Lima started in 1976,
0:05:03 > 0:05:06which, er, entailed putting three new platforms in,
0:05:06 > 0:05:07and the first one was in Lima.
0:05:07 > 0:05:11More than 30 years later, Mick finds himself back out
0:05:11 > 0:05:14in the North Sea, working on Lima again,
0:05:14 > 0:05:16at the very heart of the decommissioning process.
0:05:17 > 0:05:19I got a phone call saying,
0:05:19 > 0:05:23"We need a company rep on board the heavy-lift vessel Stanislav Yudin
0:05:23 > 0:05:26"taking out the platforms," would I be interested?
0:05:26 > 0:05:28And I said, "Too right, I would."
0:05:28 > 0:05:30The challenge of working at sea
0:05:30 > 0:05:33makes the complex decommissioning process more costly,
0:05:33 > 0:05:36more difficult and more dangerous.
0:05:36 > 0:05:39Massive heavy-lifting vessel the Stanislav Yudin,
0:05:39 > 0:05:42weighing almost 25,000 tonnes,
0:05:42 > 0:05:45has moored up against Lima.
0:05:45 > 0:05:48This mobile demolition yard
0:05:48 > 0:05:51costs half a million pounds to hire per day,
0:05:51 > 0:05:55and will be home to the 120 engineers
0:05:55 > 0:05:57who will harvest Lima from the sea.
0:05:57 > 0:06:01Their first major job is to plug the wells and sever the gas conductors.
0:06:03 > 0:06:05The Lima platform had six wells,
0:06:05 > 0:06:09each tapping into a separate section of the gas reservoir,
0:06:09 > 0:06:10two miles under the sea.
0:06:10 > 0:06:14The only way to bore that deep is to brace the well in sections
0:06:14 > 0:06:16as it's drilled.
0:06:16 > 0:06:19Each time, a smaller pipe is passed down,
0:06:19 > 0:06:21and the join is sealed with concrete.
0:06:21 > 0:06:23These are known as conductors.
0:06:23 > 0:06:27Now, Lima's wells have been plugged in four places with cement,
0:06:27 > 0:06:30and the conductors are ready to be cut.
0:06:31 > 0:06:34You end up with pipes within pipes within pipes.
0:06:34 > 0:06:36So you've got concentric rings of pipes.
0:06:36 > 0:06:40Once the conductors have been cut, you will actually see something
0:06:40 > 0:06:42that's like a dartboard effect,
0:06:42 > 0:06:46with concentric circles within each other, with concrete between them.
0:06:48 > 0:06:52Cutting through these materials would be a challenge on land -
0:06:52 > 0:06:57but this surgery needs to be carried out 30 metres under the surface
0:06:57 > 0:06:59of a stormy North Sea.
0:06:59 > 0:07:04Matteo Mosca helped develop an ingenious cutting solution -
0:07:04 > 0:07:08one of the many methods used in North Sea decommissioning.
0:07:08 > 0:07:10So, what have we got on there?
0:07:10 > 0:07:13On this wire, which is just a steel-strand wire,
0:07:13 > 0:07:16you've got embedded these diamond bits,
0:07:16 > 0:07:20- these elements, which are covered with synthetic diamond.- OK.
0:07:20 > 0:07:24Then, the wire is constructed as an endless loop,
0:07:24 > 0:07:25continuous, endless loop.
0:07:25 > 0:07:29- And it grinds its way through. - Yes, and gives, er,
0:07:29 > 0:07:32a good finishing - it doesn't alter the physical structure
0:07:32 > 0:07:36of the metal, locally, it doesn't heat it.
0:07:36 > 0:07:39So, can we actually see this...cut through?
0:07:39 > 0:07:40Yes.
0:07:40 > 0:07:43- That's what it's made for, so... - Let's go.
0:07:45 > 0:07:48Back out in the North Sea, this process is happening
0:07:48 > 0:07:5130 metres below the surface of the water.
0:07:53 > 0:07:56These cameras help guide divers
0:07:56 > 0:08:00as they manoeuvre the diamond wire-cutter into place.
0:08:00 > 0:08:03- MACHINE WHIRRS - Let's get cutting!
0:08:07 > 0:08:09The amount of friction created
0:08:09 > 0:08:12by the cutter can heat up the steel so much
0:08:12 > 0:08:16that it begins to warp, so it has to be cooled by water.
0:08:16 > 0:08:19The saw working out on the Inde field
0:08:19 > 0:08:21has the cold North Sea to do the job.
0:08:23 > 0:08:25But for this demonstration here on land,
0:08:25 > 0:08:28cold water must be sprayed on to dissipate the heat.
0:08:30 > 0:08:33The thing for me which drives home what a clever piece of kit it is -
0:08:33 > 0:08:37you've got thousands of tonnes compressing down...
0:08:38 > 0:08:41..and this cutter allows you to cut across that
0:08:41 > 0:08:43without it getting jammed.
0:08:43 > 0:08:46A jam deep under water would halt proceedings
0:08:46 > 0:08:49and cost tens of thousands of pounds to put right.
0:08:49 > 0:08:53But this, because it cuts all the way round that wire,
0:08:53 > 0:08:57not just forwards, but also above and beneath it,
0:08:57 > 0:09:01it allows the machine to just keep cutting and slicing
0:09:01 > 0:09:03right the way through.
0:09:03 > 0:09:07MACHINE WHIRRS
0:09:10 > 0:09:12It's a really impressive cut.
0:09:16 > 0:09:21On Lima, with the wells plugged and the conductors cut,
0:09:21 > 0:09:24they'll be able to move on to a bigger challenge -
0:09:24 > 0:09:26removing the 2,500-tonne platform.
0:09:27 > 0:09:30This scrapping represents the end of an era.
0:09:30 > 0:09:33The North Sea veterans who put Lima up
0:09:33 > 0:09:35know how tough it will be.
0:09:35 > 0:09:3734 years ago, as a young man,
0:09:37 > 0:09:40Austin Hand helped to bring it into the world.
0:09:40 > 0:09:42Now, he's in charge of decommissioning
0:09:42 > 0:09:45on one of the North Sea's biggest projects.
0:09:47 > 0:09:50- Is this you here? - That's me and my boss, Gordon Box,
0:09:50 > 0:09:53who was the guy who actually recruited me into Shell.
0:09:53 > 0:09:55I've been involved in that sense for 40 years,
0:09:55 > 0:09:57either design and construct..
0:09:57 > 0:10:00And initially, my first sort of foray into the offshore business
0:10:00 > 0:10:03- was, er, Inde Lima. - That's Lima in the background?
0:10:03 > 0:10:06That's it, parked in the quayside in Lowestoft,
0:10:06 > 0:10:08after we'd brought it down from Middlesbrough.
0:10:08 > 0:10:11So, that was us beginning to get it ready to go.
0:10:14 > 0:10:18The platform has to withstand 15-metre-high waves
0:10:18 > 0:10:21and winds of up to 100mph.
0:10:21 > 0:10:23The legs - or jacket - is all-important,
0:10:23 > 0:10:25fixing Lima to the sea bed.
0:10:25 > 0:10:28Removing it is going to be a mammoth task,
0:10:28 > 0:10:31and will require as much engineering ingenuity
0:10:31 > 0:10:33as went into building her.
0:10:33 > 0:10:38So, the jacket's basically a frame, and you place it on the sea bed,
0:10:38 > 0:10:41then you put piles in, like, pinning it,
0:10:41 > 0:10:44and you drive the piles with a big hammer into the sea bed.
0:10:44 > 0:10:47That is a piling hammer. It's about 60ft high.
0:10:47 > 0:10:51Now, above all these exciting things to do,
0:10:51 > 0:10:54one of my jobs was to stand out all night
0:10:54 > 0:10:57with a clicker, counting the number of blows of the piling hammer.
0:10:57 > 0:10:59You got all the good jobs!
0:11:00 > 0:11:03Lima's removal from the North Sea will involve taking away
0:11:03 > 0:11:07not just the jacket, but the piles as well.
0:11:07 > 0:11:10And before that happens, I want to understand exactly
0:11:10 > 0:11:13how she was constructed and secured out at sea.
0:11:13 > 0:11:15- I've got to show you how it works. - OK.
0:11:15 > 0:11:18Right, so, obviously,
0:11:18 > 0:11:20on Lima, this was done...
0:11:20 > 0:11:23a helluva lot further out at sea!
0:11:23 > 0:11:24How do they actually get it out?
0:11:24 > 0:11:27- They built this on land, the jacket. - Yeah?
0:11:27 > 0:11:29They took it out on a massive barge, though.
0:11:29 > 0:11:35But the jacket is basically only there as a guide for the piles.
0:11:35 > 0:11:38And these are what takes the whole force
0:11:38 > 0:11:40of the topside - so they go...
0:11:40 > 0:11:44slot down into each of the legs. So, on Lima,
0:11:44 > 0:11:46these piles...
0:11:46 > 0:11:50were being driven 90ft into the sea bed.
0:11:53 > 0:11:56Must be a very noisy job!
0:11:56 > 0:11:58It IS a very noisy job!
0:11:58 > 0:12:01That's why they do it so far out at sea, so they don't disturb anyone!
0:12:01 > 0:12:03Ha-ha-ha-ha!
0:12:03 > 0:12:06That is going nowhere!
0:12:08 > 0:12:12'With the legs firmly embedded, the final part of the construction
0:12:12 > 0:12:14'was to add the topside.'
0:12:14 > 0:12:19Now, 40 years on, removing that topside
0:12:19 > 0:12:21is about to be the biggest test so far
0:12:21 > 0:12:24for Lima's decommissioning team.
0:12:27 > 0:12:30Weighing in at 1,350 tonnes,
0:12:30 > 0:12:33this is the heart of the rig, where the crew lived and worked,
0:12:33 > 0:12:37processing the gas before piping it to shore.
0:12:38 > 0:12:42Cutting it off the legs will be an enormous challenge,
0:12:42 > 0:12:45requiring knowledge, skill and nerves of steel.
0:12:45 > 0:12:48The problem is, how do you cut across the legs
0:12:48 > 0:12:52but still ensure the platform stays in place until craned off?
0:12:54 > 0:12:57If, for some reason, we had a storm blow up,
0:12:57 > 0:12:59and we just did a straight cut,
0:12:59 > 0:13:02potentially, the wind and the weather could vibrate the topsides
0:13:02 > 0:13:05and start to move the topsides.
0:13:05 > 0:13:09If it's just on a flat surface, it could start to move,
0:13:09 > 0:13:13and potentially, the last thing I want to do is have to go fishing
0:13:13 > 0:13:15to get the topsides off the sea bed.
0:13:15 > 0:13:19Lives could be at stake if they get it wrong,
0:13:19 > 0:13:21and so a simple but ingenious solution
0:13:21 > 0:13:24is integrated into how they sever the legs.
0:13:26 > 0:13:30The cuts are shaped like castle ramparts.
0:13:30 > 0:13:32These cuts are absolutely genius,
0:13:32 > 0:13:35and crucial to the whole decommissioning process.
0:13:35 > 0:13:37Having made the cut through the jacket,
0:13:37 > 0:13:41the topside is resting on that. What the castellations do
0:13:41 > 0:13:44is to give the whole thing a lot more structural integrity.
0:13:44 > 0:13:47But when you do need it to be lifted, the crane comes in
0:13:47 > 0:13:49and it's taken up - genius.
0:13:51 > 0:13:55The final, castellated cuts are made to Lima's legs, leaving her
0:13:55 > 0:13:591,300-tonne topside precariously balanced on top.
0:14:01 > 0:14:03The worst thing that could happen at this stage
0:14:03 > 0:14:05is a storm.
0:14:05 > 0:14:07WIND BLOWS
0:14:07 > 0:14:12The castellations could be brutally put to the test.
0:14:21 > 0:14:25But the morning sun reveals that Lima's topside
0:14:25 > 0:14:28is still in place. Now, it faces a new test.
0:14:31 > 0:14:36This part of the operation is incredibly dangerous.
0:14:36 > 0:14:40It uses a floating crane that can lift 2,500 tonnes.
0:14:40 > 0:14:43That's as much as the Blackpool Tower weighs,
0:14:43 > 0:14:46which is why it costs almost half a million pounds to hire -
0:14:46 > 0:14:50every day. Then, in order to float more than
0:14:50 > 0:14:542,000 tonnes of steel back to land, a barge is needed.
0:14:54 > 0:14:58This one is as big as a football pitch.
0:14:58 > 0:15:02At this moment, there's only one thought running through Mick's mind.
0:15:02 > 0:15:06- Is it going to be level?- The lift is based on complex calculations,
0:15:06 > 0:15:10which allow the crane to ballast itself against Lima's weight.
0:15:10 > 0:15:13But these calculations are estimates.
0:15:13 > 0:15:16So, you're doing a theoretical model
0:15:16 > 0:15:19of, er, not only the topsides' weight,
0:15:19 > 0:15:22but where the centre of gravity of the topsides is.
0:15:23 > 0:15:26And they're about to find out how close to the truth they are.
0:15:35 > 0:15:38The platform is successfully lifted off its legs
0:15:38 > 0:15:41for the first time in 30 years.
0:15:55 > 0:15:59More than 1,000 tonnes of steel are manoeuvred with precision
0:15:59 > 0:16:01safely onto the barge.
0:16:06 > 0:16:10With stage one complete, the engineers will
0:16:10 > 0:16:12turn their attention to the legs.
0:16:12 > 0:16:15These are embedded deep into the bedrock, and must be cut off
0:16:15 > 0:16:17below the surface of the sea bed.
0:16:17 > 0:16:20The task is tricky, and will require an even more ingenious solution.
0:16:22 > 0:16:27As preparation for Lima to leave the Indefatigable gas field continues,
0:16:27 > 0:16:28I want to find out more
0:16:28 > 0:16:31about why she ended up there in the first place.
0:16:31 > 0:16:34For geologist John Underhill, gas and oil exploration
0:16:34 > 0:16:36is a lifetime's work.
0:16:36 > 0:16:39I have this strange belief that under the sea,
0:16:39 > 0:16:42when you go drilling for oil, there exist pools of oil,
0:16:42 > 0:16:45pockets of gas, large, you know, sealed-off sections
0:16:45 > 0:16:49that we drill and tap into, and it all comes out - is that true?
0:16:49 > 0:16:52Well, it's a popular myth, really, that we float
0:16:52 > 0:16:54on a reservoir of oil - in reality,
0:16:54 > 0:16:58it's solid rock, er, with what's called pore space
0:16:58 > 0:17:01between it - so, air pockets that can be filled with gas or with oil.
0:17:01 > 0:17:05These air pockets, less than a millimetre in size,
0:17:05 > 0:17:08fill up with gas over millions of years.
0:17:08 > 0:17:11The pores make this kind of rock soft and easy to drill -
0:17:11 > 0:17:14so soft, you can even feel it.
0:17:14 > 0:17:16I'm moving grains of sand -
0:17:16 > 0:17:18they're coming apart and they're on my fingers,
0:17:18 > 0:17:21so that's breaking apart, that is a porous rock.
0:17:22 > 0:17:23The very same rock formation
0:17:23 > 0:17:26that makes up Lima's gas field off the Norfolk coast
0:17:26 > 0:17:28travels the length of England,
0:17:28 > 0:17:32and emerges on land here at Tynemouth in the north-east.
0:17:32 > 0:17:35This is a core from the North Sea, from the Inde field.
0:17:35 > 0:17:37Can I hold this...this precious ingot?
0:17:37 > 0:17:41And from a sample like this, once in the hands of the geologists,
0:17:41 > 0:17:44and tested for all its components,
0:17:44 > 0:17:47you can then say how rich it is in oil or gas or...?
0:17:47 > 0:17:50We can calculate how much gas is in the Inde field, for example,
0:17:50 > 0:17:53from this and from the mapping of the seismic data.
0:17:53 > 0:17:56Geologists calculated that the Inde field
0:17:56 > 0:18:00contained 5.6 trillion cubic feet of gas -
0:18:00 > 0:18:04enough to fill nearly 2 million Wembley stadiums.
0:18:07 > 0:18:09Under the right conditions,
0:18:09 > 0:18:12gas is formed from the remains of organic matter,
0:18:12 > 0:18:14compressed under rock for millions of years.
0:18:14 > 0:18:18This layer is known as the carboniferous layer,
0:18:18 > 0:18:19or source rock.
0:18:19 > 0:18:23Above this, porous rock holds the gas like water in a sponge,
0:18:23 > 0:18:26in the gaps between its grains.
0:18:26 > 0:18:28Finally, a layer of hard, non-porous rock,
0:18:28 > 0:18:31known as the sealing layer, forms a cap,
0:18:31 > 0:18:35locking in all the gas - until someone drills a well.
0:18:37 > 0:18:40There are two types of source rock - one is oil-prone,
0:18:40 > 0:18:43and comes from either marine, erm, sediments
0:18:43 > 0:18:46or lake sediments. The other type
0:18:46 > 0:18:50is from woody material - coal, that gives a gas-prone source rock.
0:18:50 > 0:18:54So it's marine life that gives us oil, and then...
0:18:54 > 0:18:58- land life that gives us gas. - Primarily, yes.
0:18:58 > 0:19:02And here, in the cliff face below Tynemouth Priory,
0:19:02 > 0:19:05we can see how the source rock lies beneath the sealing layer -
0:19:05 > 0:19:09identical to that found in the Inde field.
0:19:10 > 0:19:13At the base, we've got the carboniferous,
0:19:13 > 0:19:16which is the...the source rock level.
0:19:16 > 0:19:20Above that, we have the reservoir unit, the yellow sands,
0:19:20 > 0:19:24and above that, the recess right at the top of the cliff
0:19:24 > 0:19:28is the sealing unit, which keeps the gas in the reservoir
0:19:28 > 0:19:33underneath the North Sea, and all three are exposed here
0:19:33 > 0:19:35in this cliff line.
0:19:37 > 0:19:42Out in the North Sea, with Lima's 1,300-tonne topside removed,
0:19:42 > 0:19:45the next big challenge is to sever the ten-storey-high,
0:19:45 > 0:19:481,085-tonne legs from the sea bed.
0:19:50 > 0:19:52All trace of Lima must be removed
0:19:52 > 0:19:55to satisfy a so-called clean sea policy,
0:19:55 > 0:19:59triggered by a dramatic event in the North Sea 17 years ago.
0:20:02 > 0:20:05The Brent Spar was a gigantic oil storage facility,
0:20:05 > 0:20:09from which oil tankers transported the oil to shore.
0:20:09 > 0:20:13By 1995, a pipeline had been installed,
0:20:13 > 0:20:16so it was no longer needed. Shell had a plan to dump it
0:20:16 > 0:20:20by towing it into the Atlantic and sinking it.
0:20:20 > 0:20:25Greenpeace saw this as a potential environmental disaster,
0:20:25 > 0:20:27so they sailed out and took control of the Spar -
0:20:27 > 0:20:30a protest that would make international news.
0:20:30 > 0:20:34In a blaze of bad publicity, Shell reversed their decision
0:20:34 > 0:20:37and instead towed it to shore to be recycled on land
0:20:37 > 0:20:41and put the rest of the Brent field decommissioning on ice.
0:20:41 > 0:20:4417 years later, the process has restarted,
0:20:44 > 0:20:49and Austin Hand, who began his offshore career building Lima,
0:20:49 > 0:20:51is in charge.
0:20:51 > 0:20:53Did that kind of act as a precedent for now
0:20:53 > 0:20:56how all the fields and platforms are decommissioned?
0:20:56 > 0:20:59We thought it was a reasonable and logical thing to do,
0:20:59 > 0:21:04to take it out to sea, 2.5 miles down in the Atlantic,
0:21:04 > 0:21:07and place it in this kind of valley on the sea bed.
0:21:07 > 0:21:12Er, we didn't do a very good job of explaining that, so basically,
0:21:12 > 0:21:16that resulted in the Oslo-Paris Convention of 1998, that said,
0:21:16 > 0:21:19roughly speaking, "You put them there, you take them away."
0:21:19 > 0:21:22- A clean seas policy.- OK. - That's what Greenpeace strove for,
0:21:22 > 0:21:24and that's what they succeeded in getting.
0:21:24 > 0:21:29There's so much involved in this that the cost of decommissioning
0:21:29 > 0:21:32- just must be enormous. - Austin's estimate, Austin's view -
0:21:32 > 0:21:34100 billion.
0:21:34 > 0:21:37- Of decommissioning...- In the UK.
0:21:37 > 0:21:41There are those that would say, "I don't believe you, Austin,
0:21:41 > 0:21:43"you've over-stated it."
0:21:43 > 0:21:45We'll see who's right in the end.
0:21:47 > 0:21:50Because of the clean seas policy, out in the North Sea,
0:21:50 > 0:21:54the Lima engineers now face a really difficult challenge -
0:21:54 > 0:21:58cutting the legs of the jacket to remove it from the sea bed
0:21:58 > 0:22:01in a way that leaves no trace that it was ever there.
0:22:03 > 0:22:06To achieve this, the jacket legs must be cut off
0:22:06 > 0:22:09three metres below the sea bed.
0:22:09 > 0:22:11This means the only way to cut the legs
0:22:11 > 0:22:13is to sever them from the inside.
0:22:13 > 0:22:17It's a job that demands a very special type of cutter.
0:22:17 > 0:22:21As world expert George Jack explains, there's no blade,
0:22:21 > 0:22:24no flame - just water and grit.
0:22:26 > 0:22:29Is it the sea water that you're using there?
0:22:29 > 0:22:32Yeah, we filter sea water in through our pumps,
0:22:32 > 0:22:34take it up to high pressure,
0:22:34 > 0:22:37and introduce the abrasive to it as well.
0:22:37 > 0:22:40That's the actual garnet that we introduce to the water.
0:22:40 > 0:22:42- That's pretty hard stuff?- Yeah...
0:22:42 > 0:22:45'Garnet is a dark red, silicon-based mineral.
0:22:45 > 0:22:48Although large crystals are used in jewellery,
0:22:48 > 0:22:51some types possess strong atomic bonds, which make them very hard,
0:22:51 > 0:22:54and ideal as industrial abrasives.
0:22:55 > 0:22:58If you don't have that in your water,
0:22:58 > 0:23:00there's not enough, er, friction
0:23:00 > 0:23:02- to cut through the actual metal.- OK.
0:23:02 > 0:23:05George is about to demonstrate to me the power
0:23:05 > 0:23:07of cutting with water and garnet.
0:23:07 > 0:23:11This is the control room, where we control the water pressure,
0:23:11 > 0:23:15- the grit monitor...- So, what pressure are we at at the moment?
0:23:15 > 0:23:18- Just now, we're sitting at 6,000 PSI. - OK...
0:23:18 > 0:23:20'That's 300-400 times greater
0:23:20 > 0:23:23'than your typical water supply at home.'
0:23:23 > 0:23:26- So, abrasives on. - Yes, that will put your...
0:23:26 > 0:23:30introduce the grit into the system, and the pressure comes up.
0:23:31 > 0:23:32Here we go!
0:23:32 > 0:23:34He-he! Look at that!
0:23:34 > 0:23:37As soon as it starts coming through,
0:23:37 > 0:23:40you'll see the water coming underneath.
0:23:43 > 0:23:45Who-hoah!
0:23:45 > 0:23:47- Now!- Now you can see it's just gone through!
0:23:51 > 0:23:56- So, that's 50mm of solid steel, that's just cut.- 50mm, yeah.
0:23:56 > 0:24:00Compared to, say, a high-pressure jet hose that you might get for
0:24:00 > 0:24:03- washing your car or doing your patio from the hardware store...- Yeah.
0:24:03 > 0:24:05..if you tried to do that with this thing,
0:24:05 > 0:24:09- you'd do more damage than good, right?- Oh, yeah.
0:24:09 > 0:24:13The pressure we can barely read on one of these gauges -
0:24:13 > 0:24:17the first line on that, it goes up in thousands...
0:24:21 > 0:24:23I'm not sure what kind of cut I'm expecting.
0:24:23 > 0:24:26Is it going to be a clean cut? Will it be quite jagged?
0:24:26 > 0:24:28Here we go.
0:24:28 > 0:24:31Wow! That's clean. That's a really
0:24:31 > 0:24:33- straight, clean cut. - Surprising, isn't it?
0:24:33 > 0:24:36Bit of the old Paul Daniels, Debbie McGee -
0:24:36 > 0:24:38- it's gone right the way through. - Yep!
0:24:38 > 0:24:40- So, this is not for domestic use. - No.
0:24:40 > 0:24:43Not for domestic use, I'm afraid!
0:24:46 > 0:24:50The Lima engineers are ready for the high-pressure water cutter.
0:24:50 > 0:24:54With the topside removed, they're able to lower it down,
0:24:54 > 0:24:57right inside the legs.
0:24:57 > 0:25:00In theory, if the severance isn't complete,
0:25:00 > 0:25:04the crane could pull the Stanislav Yudin over.
0:25:04 > 0:25:07In practice, fail-safe mechanisms would prevail.
0:25:07 > 0:25:10But an incomplete severance could still cost millions.
0:25:10 > 0:25:14- We control it from the topside using hydraulics and everything.- OK.
0:25:14 > 0:25:18And it'll cut...do a 360 degrees,
0:25:18 > 0:25:21sub-sea, just three metres below the sea bed.
0:25:22 > 0:25:26Before they begin the cutting, every precaution must be taken.
0:25:27 > 0:25:31The system is pressurised to 6,000lb per square inch.
0:25:31 > 0:25:34Any leak or breach could be deadly.
0:25:35 > 0:25:39An exclusion zone around the cutter is strictly enforced.
0:25:40 > 0:25:43We've got high-pressure hoses running across the deck.
0:25:43 > 0:25:45If you put your hand up like that...
0:25:45 > 0:25:47you're not going to have anything left.
0:25:47 > 0:25:50Calculations estimate that the 360-degree cut
0:25:50 > 0:25:53of each leg should take 75 minutes.
0:25:53 > 0:25:57All Mick can do now is time it and hope.
0:26:01 > 0:26:04Once the allotted time has been given to each leg,
0:26:04 > 0:26:07special slings are attached.
0:26:10 > 0:26:12So all the slings are...
0:26:12 > 0:26:15They're not just something you get off a shelf.
0:26:15 > 0:26:18All the slings are engineered and designed
0:26:18 > 0:26:21and built to the length required.
0:26:21 > 0:26:25Now the crane must ballast itself against an unknown payload.
0:26:25 > 0:26:28Up to 300 tonnes of extra weight in marine life
0:26:28 > 0:26:31could have accumulated over four decades,
0:26:31 > 0:26:36making the jacket 1,400 tonnes - as heavy as seven jumbo jets.
0:26:37 > 0:26:43All this makes the calculations for the stability of the crane more and more difficult,
0:26:43 > 0:26:47puts the ballasting power of the Stanislav Yudin yet further to the test,
0:26:47 > 0:26:50and her stability in more jeopardy.
0:26:51 > 0:26:54And then the big, tense moment for everybody...
0:26:57 > 0:27:01..because we are now going to start to lift the jacket.
0:27:01 > 0:27:04But there's one thing we can't do - we can't actually 100% guarantee
0:27:04 > 0:27:07they're cut by going and having a look at them.
0:27:11 > 0:27:13You hear the crane driver,
0:27:13 > 0:27:17he starts taking the weight on the crane...
0:27:18 > 0:27:20..1,200, 1,400 tonnes, somewhere in that region.
0:27:20 > 0:27:22And if he gets to 1,400 tonnes
0:27:22 > 0:27:25and then he starts saying, "I'm at 1,450 now,"
0:27:25 > 0:27:29you're thinking, "I hope this is going to move shortly."
0:27:31 > 0:27:35And your heart's probably going "thump, thump, thump."
0:27:35 > 0:27:38And then, all of a sudden, it just seems to go, "Ooh!"
0:27:44 > 0:27:48And it's a great sight, that, and it's a great relief.
0:28:09 > 0:28:13After the final lift, engineers work through the night to fasten
0:28:13 > 0:28:18Lima safely to the barge upon which she'll make her final journey.
0:28:22 > 0:28:25And that was it, it was an end of an era
0:28:25 > 0:28:29for, not only myself, but for so many people
0:28:29 > 0:28:34that have worked on the Inde field throughout the last 40 years.
0:28:35 > 0:28:40In the dead of night, she leaves the Inde field behind for ever
0:28:40 > 0:28:44and sets off on the 200-mile journey home to the north-east.
0:28:44 > 0:28:48Mick's relationship with Lima has finally come to an end.
0:28:49 > 0:28:54Inde produced for so long, it brought lots of people work,
0:28:54 > 0:28:58and, more than that, lots of great friends and happy memories.
0:28:58 > 0:29:00I think that's what'll stick.
0:29:02 > 0:29:03I'm now choking up.
0:29:06 > 0:29:08Oh, dear.
0:29:08 > 0:29:09I can't believe it.
0:29:10 > 0:29:13Excuse me.
0:29:14 > 0:29:19But, for Lima, this marks the start of the next phase of deconstruction.
0:29:20 > 0:29:23As dawn breaks over the horizon,
0:29:23 > 0:29:26Lima arrives at the mouth of the River Tyne.
0:29:26 > 0:29:31From here, she'll be taken to the famous Swan Hunter shipyard for demolition.
0:29:31 > 0:29:34It's amazing to think something like Lima, how important that was to us.
0:29:34 > 0:29:36We just don't really consider that at all, really.
0:29:36 > 0:29:40It's delivering all that gas to our homes, keeping us warm, cooking our food...
0:29:42 > 0:29:44Well, the Inde field actually produced enough gas
0:29:44 > 0:29:48in its lifetime to power the UK for a year and a half.
0:29:48 > 0:29:50- Just in one gas field?- Yeah.
0:29:50 > 0:29:54At the Swan Hunter shipyard, they must wait for the tide
0:29:54 > 0:29:57to be just the right height, so the barge is level with the quay.
0:29:58 > 0:30:01Only then can the painstaking process of sliding
0:30:01 > 0:30:05over 2,000 tonnes of steel off the barge on to land begin.
0:30:06 > 0:30:09You don't see one of them come over every day, do you?
0:30:09 > 0:30:14Four remotely controlled bogies, with a total of 56 axles,
0:30:14 > 0:30:17each capable of supporting 36 tonnes of weight...
0:30:17 > 0:30:19Fantastic.
0:30:19 > 0:30:21..manoeuvre Lima into her final resting place.
0:30:21 > 0:30:25Now the next chapter in her story is about to begin.
0:30:26 > 0:30:28Ivan Rayne is Geordie born and bred,
0:30:28 > 0:30:30and is another person whose relationship with Lima
0:30:30 > 0:30:34and her sister platforms goes back to their construction in the 1970s.
0:30:34 > 0:30:38I bet you didn't have to wear all this kind of stuff back in the '70s, did you?
0:30:38 > 0:30:40Yeah, we did, but once you got offshore,
0:30:40 > 0:30:42if you ever mentioned the word "safety,"
0:30:42 > 0:30:45you were on the next helicopter home again.
0:30:45 > 0:30:48He, too, has come a complete circle.
0:30:48 > 0:30:51He's now here to oversee the demolition and recycling of Lima.
0:30:51 > 0:30:54All these pipes and valves and the kind of meat, everything we can see,
0:30:54 > 0:30:57it's all dedicated to getting that gas up and out of here.
0:30:57 > 0:31:02The main function of this platform is to gather gas from the seabed,
0:31:02 > 0:31:05and the gas would be brought up through six pipes,
0:31:05 > 0:31:07brought into this system here,
0:31:07 > 0:31:11and then redirected to another complex, where it is collected
0:31:11 > 0:31:15and then it's sent to the UK mainland for refining.
0:31:15 > 0:31:18Then it gets redistributed throughout the UK,
0:31:18 > 0:31:20then it comes into your house and that's what you use
0:31:20 > 0:31:22for cooking your roast beef on a Sunday.
0:31:24 > 0:31:28For Veolia's recycling team in charge of the demolition,
0:31:28 > 0:31:30this is no ordinary take-down job.
0:31:31 > 0:31:34So, this has been out in the North Sea for 40 years.
0:31:34 > 0:31:36Where do you start in taking it all apart and recycling it?
0:31:37 > 0:31:40The helideck will be cut off and pulled over,
0:31:40 > 0:31:43then we'll start dismantling it, section by section.
0:31:46 > 0:31:49Once that's flattened, they'll start cutting it up into
0:31:49 > 0:31:52very manageable pieces, and the smaller the pieces,
0:31:52 > 0:31:55the better the value they get for recycling for transport off the site.
0:31:57 > 0:31:59All right, so now we're talking money.
0:31:59 > 0:32:03Typically, what are we looking at for recycling this whole platform?
0:32:03 > 0:32:09You could be looking at anything from £180-£200,000 scrap value.
0:32:15 > 0:32:19After 40 years of service, providing gas to millions of people,
0:32:19 > 0:32:23and jobs and even a home to hundreds of North Sea Tigers,
0:32:23 > 0:32:25Lima is finally about to be brought to her knees.
0:32:29 > 0:32:32First, her infrastructure is weakened by strategic cuts.
0:32:35 > 0:32:39Next, it's time for the excavators to really get to work.
0:32:43 > 0:32:45Steel wires are attached to the helideck
0:32:45 > 0:32:48and the machines go into reverse.
0:32:59 > 0:33:02This red accommodation module is next for demolition.
0:33:02 > 0:33:05Its fixings to Lima's frame have been severed,
0:33:05 > 0:33:08and the excavators are standing by.
0:33:30 > 0:33:33'Mick Cubitt spent four years living and working
0:33:33 > 0:33:35'on Lima as an electrical engineer.
0:33:35 > 0:33:39'It's almost 19 years to the day since she last saw her.'
0:33:39 > 0:33:43That is incredible. It's like a bomb...
0:33:43 > 0:33:45A bomb has hit the place.
0:33:45 > 0:33:48In fact, it's bordering on unrecognisable.
0:33:48 > 0:33:51I don't want to pull any more emotional punches on you,
0:33:51 > 0:33:53but I think that is your old bedroom,
0:33:53 > 0:33:56that red tin shack over that.
0:33:56 > 0:34:00I'm afraid so. I spent several... in effect, the equivalent to two years' worth.
0:34:00 > 0:34:04- So...- Four years, half on, half off.- That's right.
0:34:04 > 0:34:09Some 700 nights spent in that little tin box.
0:34:17 > 0:34:20We're about to walk into your accommodation block,
0:34:20 > 0:34:25- this is home sweet home.- Home sweet home looks fairly devastating to me.
0:34:25 > 0:34:28It's really had the insides ripped out of it.
0:34:28 > 0:34:31So this was the living area, was it? This is where you passed the time?
0:34:31 > 0:34:36Well, prior to the introduction of satellite television,
0:34:36 > 0:34:40we used to show films that were hired in by the company.
0:34:40 > 0:34:42- Like your own little Blockbuster! - Yes!
0:34:44 > 0:34:47So, Mick, this must have been pretty cramped. How many people lived in here?
0:34:47 > 0:34:51This was accommodation for eight people, two lots of bunks.
0:34:51 > 0:34:56Um, the shower for all four was in here.
0:34:56 > 0:35:01That's the shower tray, with a wash basin just here.
0:35:01 > 0:35:04Shower, wash basin.
0:35:04 > 0:35:06That was your emergency exit.
0:35:06 > 0:35:07So, it's the middle of the night,
0:35:07 > 0:35:11you're asleep in your comfortable abode and there's an emergency alarm.
0:35:11 > 0:35:14The worst-case scenario. What's the order of service?
0:35:14 > 0:35:18Three offs. The three offs being block off,
0:35:18 > 0:35:21we would block in all the wells, stop the gas coming onto the platform.
0:35:21 > 0:35:26- You would then vent off.- What's the third off?- You just- BLEEP- off!
0:35:26 > 0:35:27- Follow me.- OK.
0:35:29 > 0:35:32Quickly, Mick, it's an emergency situation!
0:35:32 > 0:35:36For Mick's Lima colleagues,
0:35:36 > 0:35:39reunited in Lowestoft for the first time in over 20 years, all that's
0:35:39 > 0:35:43left are photos and shared memories of their incredible offshore lives.
0:35:43 > 0:35:47- Is this you?- That is me on Lima.
0:35:47 > 0:35:50How many times would you have been offshore at that stage, do you reckon?
0:35:50 > 0:35:54Probably not many. We used to fish, didn't we, Tony?
0:35:54 > 0:35:57- There is some entertainment to be had.- Made our own entertainment.
0:35:57 > 0:35:59What was the food supplies like, did you eat well?
0:35:59 > 0:36:03Ate very well. You would have a choice of a fillet steak, a bit of fish.
0:36:03 > 0:36:07- That's a decent spread, isn't it? - It is indeed.- Christmas crackers.
0:36:07 > 0:36:09Explosive devices offshore!
0:36:09 > 0:36:11LAUGHTER
0:36:11 > 0:36:15If you had a good chef, you had a good platform, and you'd a productive platform.
0:36:15 > 0:36:19One thing I really take away from this whole process
0:36:19 > 0:36:22is it isn't just the hardware, it isn't just the steel and everything.
0:36:22 > 0:36:26- It's the family.- It's the family of all the people who've built it, worked on it.
0:36:26 > 0:36:30How does it feel now that that particular field and Lima platform is not there any more?
0:36:30 > 0:36:34Does it kind of sit with you, does it rest with you, or...?
0:36:34 > 0:36:41When you finish, you think, "That's 40 years of my life. Now gone."
0:36:41 > 0:36:44You just realise how old you're bloody getting!
0:36:47 > 0:36:50Back at the Swan Hunter shipyard,
0:36:50 > 0:36:53another relic of the glory days of the North Sea has been uncovered,
0:36:53 > 0:36:56a stark reminder of just how treacherous it can be.
0:36:56 > 0:37:00This looks like a horror story, but I believe it was just a helideck,
0:37:00 > 0:37:03when they removed it, it smashed into the front.
0:37:03 > 0:37:08- But this is your survival raft. - Yes, this was the Brucker capsule, as it was known, on the platform.
0:37:08 > 0:37:14Awful thing to steer, being circular, and an awful thing to ride in.
0:37:14 > 0:37:16Were you the captain?
0:37:16 > 0:37:21I've done the coxon's training on here, and I've been to see with guys who are happily throwing up,
0:37:21 > 0:37:26and it is not the best place to be, even with a dozen guys in,
0:37:26 > 0:37:31when you've got a couple of them throwing up into their hard hat.
0:37:34 > 0:37:37I'm hoping that years of training means that my Lima veterans
0:37:37 > 0:37:39have grown stronger stomachs,
0:37:39 > 0:37:43because I'm about to get my first taste of the Brucker pod experience.
0:37:43 > 0:37:46This is exactly the kind of one you had up on Lima, is it?
0:37:46 > 0:37:49- Absolutely.- Yes, identical. - Identical.
0:37:51 > 0:37:54- Luxurious, was it? - No!- That's how we became friends!
0:37:54 > 0:37:56THEY LAUGH
0:37:56 > 0:37:59Pods like these have safely evacuated
0:37:59 > 0:38:03more than 2,000 people in over 60 incidents around the world
0:38:03 > 0:38:05since Lima was built.
0:38:07 > 0:38:09How long is it since you guys have been in one of these?
0:38:09 > 0:38:12For me, it would have been 1978, in this particular type.
0:38:12 > 0:38:15I've been given the job of releasing the capsule,
0:38:15 > 0:38:18and it's fair to say that the speed of the response takes me by surprise.
0:38:24 > 0:38:25Right, we're off.
0:38:27 > 0:38:30They were designed for the Gulf of Mexico,
0:38:30 > 0:38:36but the bobbing doughnut was no match for the waves and currents of an undulating North Sea.
0:38:36 > 0:38:39The survival pods, still vital for an industry which
0:38:39 > 0:38:42has claimed hundreds of lives, are now usually boat-shaped.
0:38:44 > 0:38:46I'm being shown at the ropes by Nick Goldspink,
0:38:46 > 0:38:48who's been teaching North Sea Tigers
0:38:48 > 0:38:51how to navigate these pods since 1989.
0:38:51 > 0:38:54I mean, we're moving around like a boat but, still, this round shape
0:38:54 > 0:38:57seems like a very odd design for a boat to me.
0:38:57 > 0:38:59Yeah, it's partly to do with strength
0:38:59 > 0:39:01and it's partly to do with ease of operation.
0:39:01 > 0:39:05The traditional style of lifeboat has got a cable at the front and the back,
0:39:05 > 0:39:08and there's a chance that that can hang up.
0:39:08 > 0:39:12There is no chance and no possibility of that with this shape of boat.
0:39:12 > 0:39:15Obviously, there is a compromise to the shape,
0:39:15 > 0:39:18and that is that they do bob around like a cork.
0:39:18 > 0:39:20Round boat, though, how do you even steer this?
0:39:20 > 0:39:24Yeah, well, that is more difficult than a traditional lifeboat shape,
0:39:24 > 0:39:26but the advantage to that is they are very manoeuvrable.
0:39:26 > 0:39:29But she's steered, basically, from the tiller, here,
0:39:29 > 0:39:31which again, is unusual in a lifeboat,
0:39:31 > 0:39:34to steer a boat from the front.
0:39:34 > 0:39:35If you were to evacuate,
0:39:35 > 0:39:37how long would you be able to survive in a craft like this?
0:39:37 > 0:39:40A fairly long while would be the answer to that.
0:39:40 > 0:39:43I mean, there's enough water and food for a week.
0:39:43 > 0:39:48I would not want to be stuck in here for a week with 27 other people.
0:39:48 > 0:39:50You'd get to know them fairly well fairly quickly!
0:39:50 > 0:39:53You would become quite an intimate, an intimate team.
0:39:59 > 0:40:02- So, how was that, gents? Bring back a few memories?- Yes.
0:40:02 > 0:40:07I have to say, 20 years on, I never thought I'd be back in one of them!
0:40:09 > 0:40:13Back on Tyneside, there's nothing shipshaped about Lima,
0:40:13 > 0:40:16which is being slowly cut down girder by girder,
0:40:16 > 0:40:20making it no longer possible to trace the pathway that gas would have taken,
0:40:20 > 0:40:25snaking through miles of Lima's pipework from under the sea to our kitchen hobs.
0:40:25 > 0:40:28So, to solve the mystery of how she worked,
0:40:28 > 0:40:30I'm going to see an offshore platform in action
0:40:30 > 0:40:33and trace the fossil fuel route.
0:40:33 > 0:40:36I'm bit anxious, because I've never been on a helicopter before.
0:40:36 > 0:40:40Thanks to gas and oil, Aberdeen heliport is Europe's busiest,
0:40:40 > 0:40:43ferrying almost half a million passengers offshore every year.
0:40:43 > 0:40:46Across the North Sea, more than 100 lives have been lost
0:40:46 > 0:40:48since air transfers began,
0:40:48 > 0:40:51which is why every possible safety technique is used.
0:40:51 > 0:40:56I'm terrified, truth be known. Absolutely terrified.
0:40:56 > 0:40:58In the event of the helicopter ditching,
0:40:58 > 0:41:01this suit will increase my survival time in the freezing North Sea
0:41:01 > 0:41:05from just minutes to about seven hours,
0:41:05 > 0:41:07but I hope I don't have to put it to the test.
0:41:09 > 0:41:15After an hour of seeing nothing but sea, a platform comes into view.
0:41:22 > 0:41:26100 miles offshore from Aberdeen, in the northern North Sea,
0:41:26 > 0:41:29this is Nelson, which produces both gas and oil.
0:41:32 > 0:41:34The fossil fuel's pathway on Nelson
0:41:34 > 0:41:36is very similar to Lima's gas pathway,
0:41:36 > 0:41:40so I'm going to track the route from under the sea to our homes
0:41:40 > 0:41:42and explore how current technology works.
0:41:48 > 0:41:52While Lima had six wells, Nelson has drilled 28.
0:41:52 > 0:41:57Nelson's manager, Nick Macleod, is going to show me the drill floor.
0:41:57 > 0:42:00Wow!
0:42:01 > 0:42:03- Pretty impressive drills there! - That is impressive.
0:42:03 > 0:42:07Our wells here can go down as far as 20,000 feet.
0:42:07 > 0:42:08- 20,000 feet?- Yeah.
0:42:08 > 0:42:11And eventually we get down to what's called the pay zone, which...
0:42:11 > 0:42:14- Pay zone?- Yeah, the pay zone - that's where the money is!
0:42:14 > 0:42:18- Yeah, yeah.- That's where the oil and gas is.- OK, what happens then?
0:42:18 > 0:42:21It all spurts up, doesn't it? And everyone cheers!
0:42:21 > 0:42:23In the old days. Hopefully not these days!
0:42:23 > 0:42:29The first crucial stage for the fuel that emerges is the well bay.
0:42:29 > 0:42:33Everything is moving about and juddering. It's really noisy.
0:42:33 > 0:42:35Absolutely unbelievable.
0:42:35 > 0:42:39It's unbelievable to consider that they've made this size of machine.
0:42:39 > 0:42:40It is even more incredible
0:42:40 > 0:42:44when you realise that we're 100 miles off the coast.
0:42:44 > 0:42:47Production engineer Murdo MacDonald
0:42:47 > 0:42:50is here to explain the first step of the fossil fuel's pathway...
0:42:50 > 0:42:53- Oh!- There's not a lot of room in here.
0:42:54 > 0:42:57..which involves something known in the trade as a Christmas tree.
0:42:59 > 0:43:01Why is it actually called a Christmas tree?
0:43:01 > 0:43:04Maybe it's because they look like they've got branches coming off.
0:43:04 > 0:43:06You've got all the gauges hanging off...
0:43:06 > 0:43:08You've got quite an imagination if you...
0:43:08 > 0:43:11Aye, you've got quite a bit... You have to with two weeks offshore!
0:43:14 > 0:43:15When a well's drilled,
0:43:15 > 0:43:19the raw fuel comes up the conductors into the well bay.
0:43:19 > 0:43:23On Lima, this was gas. On Nelson, it's gas and oil.
0:43:23 > 0:43:27Here, the Christmas trees, large assemblies of valves and gauges,
0:43:27 > 0:43:31help control the flow of oil and gas entering the platform.
0:43:34 > 0:43:36- I'm ready for my first offshore job. - Five turn!
0:43:38 > 0:43:42Oh, one...two...three...four...
0:43:42 > 0:43:44Five turns!
0:43:44 > 0:43:49- What have I done?- You've just closed the choke in about 5%.
0:43:49 > 0:43:51Just closed the choke in 5%?
0:43:51 > 0:43:55- Which has restricted the oil flow coming up...?- Absolutely.
0:43:57 > 0:44:00Stage two of the pathway is all about separating
0:44:00 > 0:44:03what emerges from the well into its constituent parts.
0:44:04 > 0:44:06It's like science fiction film.
0:44:06 > 0:44:10When a well is drilled, oil comes up the conductors into the well bay,
0:44:10 > 0:44:12but it's not pure oil.
0:44:12 > 0:44:16It's a mixture of oil, gas and water.
0:44:16 > 0:44:19In order to extract the valuable oil and collect the gas,
0:44:19 > 0:44:20the whole mixture is sent
0:44:20 > 0:44:25to one of the most important devices on the platform - the separator.
0:44:26 > 0:44:29I've made a model of Nelson's separator,
0:44:29 > 0:44:31to explain to Rob how it works.
0:44:31 > 0:44:33It's bafflingly simple.
0:44:33 > 0:44:36We have here a bucket, which to the casual observer
0:44:36 > 0:44:40appears to be a generic brand of cola mixed with vegetable oil,
0:44:40 > 0:44:44which is actually exactly the same as oil, water and gas, all right?
0:44:44 > 0:44:46That's from the bottom of the sea.
0:44:46 > 0:44:50We've got a pump but, normally, that's got enough pressure to be forcing itself up.
0:44:50 > 0:44:52Exactly. That would be pushed up under its own steam.
0:44:52 > 0:44:54So, what you do, you separate them out.
0:44:54 > 0:44:57- The gas will naturally float off to the top.- Yes.
0:44:57 > 0:45:01- Lighter than both of them. - So that will normally be tapped and off into wherever else...
0:45:01 > 0:45:04Exactly, that'll be tapped and processed, yeah.
0:45:04 > 0:45:05Water is heavier than oil.
0:45:05 > 0:45:09So, this weir is very important, because the oil floats on the water.
0:45:09 > 0:45:11OK, you see that easily here.
0:45:11 > 0:45:14So, the brown stuff is the water and the creamy stuff is your oil?
0:45:14 > 0:45:17Exactly. So, because the oil is floating on the water,
0:45:17 > 0:45:19it flows over the top of this weir,
0:45:19 > 0:45:24creating this secondary chamber here, which is pretty much all oil.
0:45:24 > 0:45:26So, coming out of here you get pure oil,
0:45:26 > 0:45:30coming out the bottom of this section you get flat cola -
0:45:30 > 0:45:34- or water.- Yeah. - Coming out the top, gas.- Gas.
0:45:35 > 0:45:40This separation stage of the fossil fuel's pathway is vitally important,
0:45:40 > 0:45:45because it tells the energy company how much gas and oil they are producing.
0:45:45 > 0:45:49To do this, every day, each well is taken out of production
0:45:49 > 0:45:51and diverted into the test separator.
0:45:51 > 0:45:54- Tom, pleased to meet you. - You too. How's it going?
0:45:54 > 0:45:57In the control room, Pete O'Connor is monitoring results.
0:45:57 > 0:46:00So, that's the production valve there -
0:46:00 > 0:46:02the diverter valve, which is open.
0:46:02 > 0:46:05That's the test one, which is shut.
0:46:05 > 0:46:07So, by putting it into the test separator,
0:46:07 > 0:46:10it lets us know how the well's performing,
0:46:10 > 0:46:12how much oil it's producing, how much water
0:46:12 > 0:46:13and how much gas it's producing.
0:46:13 > 0:46:15All our wells, now, are starting to water out.
0:46:15 > 0:46:19- They're all over 80% water. - And that didn't used to be the case?
0:46:19 > 0:46:25No. No, they all gradually, they gradually decline in oil production.
0:46:25 > 0:46:26So, the test separator
0:46:26 > 0:46:30is actually testing the mix of oil, to gas, to water?
0:46:30 > 0:46:32- For each individual well.- Yeah.
0:46:32 > 0:46:36We have a spot rate there, which, at the moment,
0:46:36 > 0:46:40can tell you we're doing 19,357 barrels, near enough,
0:46:40 > 0:46:42- today, at the moment.- Wow!
0:46:42 > 0:46:45At that rate, Nelson produces oil
0:46:45 > 0:46:48worth around £1.5 million a day.
0:46:48 > 0:46:50Not a bad return.
0:46:51 > 0:46:54The third and final stage of the fossil fuel's pathway
0:46:54 > 0:46:55is exporting it.
0:46:57 > 0:47:00Water is cleaned and pumped overboard.
0:47:00 > 0:47:04Oil is cleaned and then pumped down the export pipeline to shore,
0:47:04 > 0:47:06but it's not all over for the gas.
0:47:06 > 0:47:09Some is exported to gas terminals.
0:47:09 > 0:47:12Excess is burnt off on the iconic flare stack.
0:47:12 > 0:47:16But most of it is diverted to something known as the gas lift
0:47:16 > 0:47:18to do an important job.
0:47:18 > 0:47:20Because of the weight of the ocean
0:47:20 > 0:47:24on this trapped reservoir of hydrocarbons,
0:47:24 > 0:47:25it's all under pressure...
0:47:25 > 0:47:28- Which is kind of like this. - Ha-ha-ha!
0:47:28 > 0:47:32- So, the moment the drill pierces it, BOOM!- Wow, you've got oil.
0:47:32 > 0:47:36The oil comes out. Now, obviously, quite soon it loses pressure.
0:47:36 > 0:47:38So, once they've been tapping the oil off...
0:47:38 > 0:47:41- So, it becomes, like, the field becomes flat?- Yes, exactly.
0:47:41 > 0:47:44It becomes flat, it becomes devoid of pressure.
0:47:44 > 0:47:48- Yeah.- So, what you do, instead of pumping it up...- Yeah.
0:47:48 > 0:47:51..you push gas down into the reservoir,
0:47:51 > 0:47:54which makes the oil light because it's got gas in it,
0:47:54 > 0:47:55which then sends it back up.
0:47:55 > 0:47:58- You basically make the world's biggest SodaStream!- Yeah!
0:47:58 > 0:48:02The gas collected from the separator is compressed, repressurised
0:48:02 > 0:48:06and then reinjected back down the well via the Christmas tree,
0:48:06 > 0:48:08forcing more precious oil up.
0:48:11 > 0:48:14The force required to do this is huge.
0:48:14 > 0:48:17On the platform, Murdo shows me where they get it from.
0:48:18 > 0:48:22It's a gas compressor, which is essentially a jet engine,
0:48:22 > 0:48:26and it's one of the noisiest things I've ever experienced.
0:48:26 > 0:48:28SHOUTING: The engine drives the power turbine,
0:48:28 > 0:48:30that drives the gas compressor.
0:48:30 > 0:48:33The gas compressor takes the pressure
0:48:33 > 0:48:35from five bar in the separator,
0:48:35 > 0:48:39takes it all the way to 147 bar.
0:48:39 > 0:48:42'That's 147 times atmospheric pressure.'
0:48:42 > 0:48:47That 147 bar is then used in the header to reinject
0:48:47 > 0:48:50back down the wells and lift the oil back up again.
0:48:50 > 0:48:53They've a powerful blow, those jet engines.
0:48:53 > 0:48:55I'd say it's quite a blow, all right.
0:48:57 > 0:49:01But while Nelson's conductors are still full of North Sea gas,
0:49:01 > 0:49:05Lima's conductors now lie severed from the rest of the platform
0:49:05 > 0:49:08on the quayside at the Swan Hunter yard near Newcastle.
0:49:09 > 0:49:13Demolishing them is going to be a feat in itself.
0:49:13 > 0:49:16Because of the way the wells are drilled and constructed,
0:49:16 > 0:49:19they end up with pipes within pipes, within pipes,
0:49:19 > 0:49:22all sealed with thick layers of cement.
0:49:22 > 0:49:25Turning this into small pieces of scrap metal requires
0:49:25 > 0:49:27a process known as bombing.
0:49:29 > 0:49:33First, the gas axe is used to cut along both sides
0:49:33 > 0:49:34of the long steel conductor.
0:49:37 > 0:49:42Then, to get at the inner pipes, the excavator steps in.
0:49:45 > 0:49:47Once it's made short work of the concrete,
0:49:47 > 0:49:50the inner steel pipes are revealed,
0:49:50 > 0:49:52and the process starts over again.
0:49:52 > 0:49:55With over a third of a kilometre of conductors to scrap,
0:49:55 > 0:49:57it's a lengthy process.
0:50:01 > 0:50:04Meanwhile, on the other side of the yard, only Lima's legs -
0:50:04 > 0:50:07or jacket as it's known - still remain.
0:50:07 > 0:50:11Built from over 1,000 tonnes of high grade steel,
0:50:11 > 0:50:14it must be broken up into small chunks to be recycled.
0:50:16 > 0:50:19The first stage is to bring the structure to its knees.
0:50:19 > 0:50:24Strategic cuts must be made so the legs collapse neatly.
0:50:24 > 0:50:25But it's a dangerous job.
0:50:25 > 0:50:28As soon as a cut is made, the platform is weakened
0:50:28 > 0:50:29and may fall at any time.
0:50:32 > 0:50:35- Are you guys responsible for felling the legs?- Yes, we are.
0:50:35 > 0:50:39I wouldn't like to be the guy who does the final cut.
0:50:39 > 0:50:42- Who's in charge of that? - Whoever wants to do it.
0:50:42 > 0:50:45The backside gets a bit twitchy when the final cut's made.
0:50:45 > 0:50:47I can well understand.
0:50:47 > 0:50:49I think if it was me, the moment the axe is finished,
0:50:49 > 0:50:52I would be turning and running. Do you actually...?
0:50:52 > 0:50:54Oh, no. There's no need to run.
0:50:56 > 0:50:59In a carefully controlled and calculated procedure,
0:50:59 > 0:51:03towlines attached to the top of the jacket will be used to pull it over.
0:51:03 > 0:51:06This is the first time this method has been attempted
0:51:06 > 0:51:07anywhere in the world.
0:51:07 > 0:51:10We attach two ropes either side of the jacket
0:51:10 > 0:51:12and a safety rope to the very back of the jacket,
0:51:12 > 0:51:15just to stop the back legs toppling the wrong way.
0:51:22 > 0:51:27The engineers have put down a bed of earth for the legs to collapse onto,
0:51:27 > 0:51:29to cushion the impact.
0:51:29 > 0:51:32- They've got two lines, haven't they? - Yeah, two pulling lines.
0:51:32 > 0:51:35These guys will take the tension up on the wire.
0:51:35 > 0:51:37Just give it a little tug.
0:51:37 > 0:51:40It's quite exciting, just the anticipation of it.
0:51:40 > 0:51:42Before it comes down.
0:51:42 > 0:51:45- Everything clear? RADIO:- 'Clear.'
0:51:45 > 0:51:48- Don't let anything in now, cos we're about ready.- 'All clear, Mick.'
0:51:48 > 0:51:52If the 30-metre-high back legs were to fall in the wrong direction,
0:51:52 > 0:51:56they could land on a factory behind the shipyard.
0:51:58 > 0:52:01- Excited to see these come down? - I love it.- Brilliant.
0:52:30 > 0:52:32- Well done.- Brilliant.
0:52:32 > 0:52:34That was awesome. Congratulations.
0:52:34 > 0:52:37- And that's the way to do it. - RADIO: 'Perfect, Ned.'
0:52:37 > 0:52:41The demolition of this jacket for recycling is the final act
0:52:41 > 0:52:44in the scrapping of the Lima platform.
0:52:46 > 0:52:48'Although veteran Lima engineer Austin Hand
0:52:48 > 0:52:50'is working in decommissioning,
0:52:50 > 0:52:56'he has not seen Lima - the platform he cut his teeth on - for 20 years.'
0:52:56 > 0:52:57There she is now.
0:52:57 > 0:52:59Wow.
0:52:59 > 0:53:00I'm so used to building things,
0:53:00 > 0:53:04so to see it dismantled and in pieces is just...
0:53:04 > 0:53:07You're probably quite used to it in this condition, in a sense.
0:53:07 > 0:53:09I can still see the module, yeah.
0:53:09 > 0:53:11- Just on a different curve of its life.- Yeah.
0:53:11 > 0:53:13That really reminds me
0:53:13 > 0:53:16of going on and off that barge for months.
0:53:16 > 0:53:18Getting it completed, just walking over the gangplank
0:53:18 > 0:53:23and working 12 or 14 hour days, every day.
0:53:23 > 0:53:27- But it was fun and exciting.- I'll bet.- Yeah. That gives me a buzz.
0:53:27 > 0:53:29We were the young pioneers in those days.
0:53:29 > 0:53:32We were the ones bringing oil and gas to the UK. It was exciting.
0:53:32 > 0:53:35Good memories.
0:53:37 > 0:53:40So, we've seen, Austin, as this process has unfolded,
0:53:40 > 0:53:41the huge machine of Lima
0:53:41 > 0:53:43being reduced to small piles of steel rubble.
0:53:43 > 0:53:46I was surprised to see so much timber on show.
0:53:46 > 0:53:47Can you tell me about this?
0:53:47 > 0:53:50They used to say in my day that the rigs were made of wood
0:53:50 > 0:53:54and men were made of steel, but that's not actually true.
0:53:54 > 0:53:57What this was is we covered the main steel deck with this timber
0:53:57 > 0:54:01so that when you were lifting stuff off the supply boats
0:54:01 > 0:54:04and landing it on the platform, you had some absorption material
0:54:04 > 0:54:08to avoid damaging the deck or even the container.
0:54:08 > 0:54:11So, all this timber here was to provide you
0:54:11 > 0:54:13with a huge cushioned area to protect the whole thing.
0:54:13 > 0:54:18- Like a massive chopping board, in way.- Absolutely, yeah.
0:54:18 > 0:54:22This steel tubing once formed the jacket that supported the topside.
0:54:22 > 0:54:25It's now been broken up into sections, ready to be recycled.
0:54:28 > 0:54:31'But to the expert eye, even these fragments reveal
0:54:31 > 0:54:35'the challenges of these early pioneering designs.'
0:54:35 > 0:54:39In the '70s, sometimes the quality wasn't that great.
0:54:39 > 0:54:40This is a good example here.
0:54:40 > 0:54:45This is a very tough angle for a welder to get in at these points.
0:54:45 > 0:54:48- Yeah, you get right down in there. - Exactly. So, in an ideal world,
0:54:48 > 0:54:51that brace would have been at less of an angle.
0:54:51 > 0:54:54Very often, the designers just wanted it to be structurally robust.
0:54:54 > 0:54:57Then, when it arrived for us to deal with in the construction yard,
0:54:57 > 0:55:00you think, "Wow, why did they do that?"
0:55:00 > 0:55:03Yes, so on paper, mathematically, it makes perfect sense.
0:55:03 > 0:55:07Exactly, but sometimes it wasn't constructible.
0:55:07 > 0:55:09But again, this was a learning process.
0:55:09 > 0:55:12We'd feed that back in to the next jacket and say,
0:55:12 > 0:55:15"Can we do this slightly differently?"
0:55:15 > 0:55:20That's how we evolved the industry, getting better and better
0:55:20 > 0:55:22and ensuring these wells were sound and solid.
0:55:22 > 0:55:25All these things had to be considered, even with a relatively
0:55:25 > 0:55:27simple structure like a jacket.
0:55:27 > 0:55:31For the final time, the excavators pull on Lima's infrastructure
0:55:31 > 0:55:33to bring down her last storey.
0:55:35 > 0:55:36The legs are going to go.
0:55:38 > 0:55:39There she goes.
0:55:52 > 0:55:55It's very sad to see that, something that you built when you were
0:55:55 > 0:56:00a 25-year-old, and you're pulling it to bits when you're a 59-year-old.
0:56:00 > 0:56:03It just shows you, time moves on. Nothing stands still.
0:56:07 > 0:56:08Lima is now unrecognisable,
0:56:08 > 0:56:13just heaps of rubble and thousands of tonnes of scrap steel.
0:56:17 > 0:56:21Amazingly, some 99% of this will be recycled.
0:56:23 > 0:56:26The wood from the decks is pulped and made into paper.
0:56:26 > 0:56:29Even the 300 tonnes of algae that collected on the legs
0:56:29 > 0:56:31will be recycled for compost.
0:56:33 > 0:56:36But most lucrative is the steel.
0:56:36 > 0:56:39Once the various grades have been separated out,
0:56:39 > 0:56:42it's then smelted and made into new girders and pipes.
0:56:42 > 0:56:45Fittingly, just half a mile down the road,
0:56:45 > 0:56:48steel from the smelted remains of machines like Lima
0:56:48 > 0:56:50are being used to build this...
0:56:56 > 0:56:58..a brand-new 21st-century platform.
0:57:01 > 0:57:05To put it in perspective, whereas Lima weighed a few hundred tonnes,
0:57:05 > 0:57:09this weighs in at a whopping 12,000 tonnes.
0:57:12 > 0:57:17Platforms like this are giving the North Sea a new lease of life.
0:57:21 > 0:57:25But Lima and its gas field are now just a memory.
0:57:29 > 0:57:34Removing it cost more than £200 million, took two years
0:57:34 > 0:57:38and over a million staff hours to recycle 2,000 tonnes of steel,
0:57:38 > 0:57:43311 tonnes of algae, find homes for two generators
0:57:43 > 0:57:46and scrap two toilets and 12 well-worn bunks.
0:57:49 > 0:57:53Ironically, some of the North Sea Tigers who pioneered
0:57:53 > 0:57:55offshore platform installation are now involved
0:57:55 > 0:57:59in the biggest new North Sea industry -
0:57:59 > 0:58:00taking them back down again.
0:58:48 > 0:58:51Subtitles by Red Bee Media Ltd