Why can't they turn the oil off?

[Noworrieshere]

I keep hearing about how the Americans can't sell all their oil and are having to pay people to take it away. I can't understand why they can't just stop taking the oil out of the ground. Does anyone know? I imagine it like a big tap you can turn off and on but I guess not.
It seems mad that you can't just turn it off.

It’s probably incredibly dangerous to just turn it off - and no it’s not as simple as a tap.

Oil processing is a hugely complex, controlled and dangerous process. It is difficult to shut the process down and not as simple as turning off a tap.

It's not a big tap at all. You can't turn it off because by drilling into the oil field you release the pressure that has been contained by rocks for thousands of years. Have you seen the old videos of prospectors digging for oil and the massive geyser that happens when you break through?

Well the same happens now (in some types of field, I know they aren't all the same, but I'm trying to keep this post simple) but much deeper underground as stocks have depleted over the years. If you allow the pressure to build too much then you can end up with an explosion in an extreme case, or a very dangerous situation when you come to "turn the tap on" again.

Source: I used to work for BP in a technical role.

Ahh this is interesting. I was wondering the same. It's not something I've thought of before, or had any interest in so wasn't sure how it all worked.

Thanks for the explanations.

Thanks, that's interesting @Rivergreen

But I also find it a bit creepy to think that we have a permanent open pipeline to the insides of the earth and that now we have started letting stuff out of there we can't stop it. I know that's not how it is really but you know what I mean.

Can we never stop it now, until it runs out?

It can't be turned off, the well has to be capped or sealed which means uncapping the well to reopen it. Prob means $$$ or the field closing then the costs of start-up are huge

Haha! @Noworrieshere, I've never thought about it like that!

What you do to stop it and how easy it is all depends on what stage you're at in the extraction process iyswim.

The first stage is as I described earlier, where the pressure of the oil basically forces it's way out once you've provided a route. If you imagine how the oil was created, with huge pressure from the rocks mushing up the organic matter, then physics basically means that when you first open up the route out the oil pressure forces out with the same pressure the earth was pushing down. But the more oil that comes out, the less pressure there is (there is more space in the well, so the oil can spread out and it's easier to do that than travel up the pipe). Letting the oil flow out by itself will only give you about 10% of the contents in the field.

So at that point, we start pumping water / gas down into the well to increase the pressure and push more oil out, which is called secondary extraction and in a good field you can get almost half the oil in this way. You can then go onto more difficult (and expensive) options once you've exhausted this method. Often it's not worth it. For example, this is the state that a lot of the north field oil supplies are in: waiting for the oil price to rise sufficiently for the cost of tertiary extraction to be worth it.

So the oil doesn't just keep pouring out regardless, quite quickly it needs assistance. I can't honestly tell you how extraction would be suspended in reality, or if you need to keep a minimum flow: I didn't do much work with extraction, I was more involved in pipelines. I would imagine that most countries would like to keep a minimum of extraction happening for practical reasons of being able to start up quickly (and beat competitors to market) when it's required. With oil, the political and economic reasons usually beat technical!

If you decide it isn't worth extracting the oil anymore, then the field can be plugged, but that's considered a permanent fix and involves a huge amount of work, so wouldn't be considered a short term solution.

Check out the film 'Deepwater Horizon'.

Also forgot to mention that extraction occurs way before sale: the oil needs to be piped and then refined before it's sold. A sharp dip in demand, like this, will mean that the huge oversupply of now was caused by oil extracted months ago.

But if you were BP, you wouldn't want to pull your workers off the rigs: when demand picks back up, you want your oil available to buy too, not just Shell's.

@gingernaut Deepwater Horizon shows how badly it can go wrong: the workers were trying to temporarily leave that particular oil field.

However, the events were caused by a series of horrendously bad decisions, bad engineering and a cavalier attitude to safety. Not by the act of leaving. Oil fields are temporarily abandoned all the time until it's economic to come back to them.

Remember it's only negative because people committed to buy it, but don't actually want it now and don't have anywhere to store it - either because they no longer need it but mostly because they were never planning to have it anyway but were hoping to profit from a difference between the price when they committed to buying it, and the price they could have got nearer the day of delivery.

But of course they never had a chance to sell it, so now they need to pay people to take it off their hands - those with the actual ability to store it. This won't happen as much going forward as the speculators won't be as in such broken positions in the future.

I imagine it like a big tap you can turn off and on

Er, no. The days when you stuck a straw in the ground and the juice kept flowing are over. Oilfield technology like directional drilling is a response to challenges to extraction. There is a glut of supply because the entire planet is on house arrest. Storage is at full capacity.

Strange, the Deepwater Horizon disaster was actually 10 years to the day on Monday.
I was on maternity leave and vividly remember the rolling news coverage of them trying to plug the well and stop the oil spewing out into the ocean. It took weeks.
I know it’s a bit different as that was a blow out, but it shows you the sheer force of the thing.

I have only very vaguely heard of Deepwater Horizon. The name is familiar but I couldn't have told you what it was about. The things you learn on lockdown! I'm off to look up the film now, but I have some weird thing about giant machinery that freaks me out so I might not want to watch it.