Offshore oil drilling is safe?

[MotoH]

You would think they could stop the oil flowing instantly after a massive explosion ripped through a rig!

Seriously now Ivan, come on.

Edit by Ivan: Very strange. Somehow I accidently moved this post to the wrong position. This post should be the second in this thread. the #2 post should be the first.

 

[Ivan Seeking]

Recently we have seen a push by Obama, as well as long-time proponents, to increase offshore oil drilling. Offshore drilling is much safer than it used to be, it is argued. While that may be true, the claim falls flat considering the oil spill still in progress, in the Gulf of Mexico. This isn't making me a believer! Right now, one expert on CNN is saying that we don't know exactly how it will be stopped. It could weeks or even months! Once again, I feel we have been lied to by industry. How could they not be prepared for something like this?! After all of the years of debate and furor over safety, this is simply unbelievable.

http://www.news-press.com/article/20100426/GREEN/100426035/1075/Gulf-states-keep-eye-on-oil-spill-study-measures-to-protect-beaches

Algae to the rescue
https://www.physicsforums.com/showthread.php?t=211274

 

[Ivan Seeking]

I thought these things were supposed to have a failsafe at the source to stop the flow in the event of an emergency. So much for that promise. It doesn't work.

 

[mgb_phys]

I thought these things were supposed to have a failsafe at the source to stop the flow in the event of an emergency. So much for that promise. It doesn't work.

The problem is this is (was!) an exploration platform - it drills the initial set of holes that the production platform would later pump the oil from. They then install a whole bunch of caps/valves/safety cut-offs/etc on the sea bed where the production platform's pipes attaches to.

It seems that when the explosion occurred they were actually installing the concrete casing that the capping valves would connect to. All they can really do at this point is try and bulldoze enough rock/mud/cement over the hole to plug. Not helped by this being in seriously deep water.

There are a lot of questions about the worker safety to be answered.
A blowout like this shouldn't have to got to the rig and the lifeboats shouldn't have had to travel for 45mins to reach the support vessel but more details of this will probably come out eventually.

 

[pallidin]

I thought these things were supposed to have a failsafe at the source to stop the flow in the event of an emergency...

Yeah, that's odd.
Not sure of the details, but I think this rig was drilling at the time(as opposed to the drilling complete and safety valves installed)

Then again, isn't there some type of "safety collar" that the drilling pipes slip through that could stop the flow during a drilling emergency? Maybe not, as I'm not sure what that "collar" could do.

Hmmm... what a mess. Hope they get it stopped and learn something from this.

 

[drankin]

As much as I would like to see more domestic production, this sux. If only they could contain and capture the mess. Maybe that ability should be a requirement before drilling.

 

[MotoH]

It is like breaking the neck off of a bottle of shaken up wine. There is a lot of pressure on that, and an explosion could rip off any fail safe devices. The only thing from my knowledge would be to tap the same hole again, or get a new hole to start relieving pressure.

 

[pallidin]

...Maybe that ability should be a requirement before drilling.

I second that vote!

 

[pallidin]

... or get a new hole to start relieving pressure.

I don't think even 3 new holes would have any significant effect on pressure.
These oil-bearing areas can be very wide/deep.
A hundred? Maybe.

 

[MotoH]

I don't think even 3 new holes would have any significant effect on pressure.
These oil-bearing areas can be very wide/deep.
A hundred? Maybe.

A new hole that starts pulling oil near the busted hole will be more effective in reducing the flow of the busted hole. Combine that with closing off the open hole, and it should be pretty effective.

 

[rootX]

A new hole that starts pulling oil near the busted hole will be more effective in reducing the flow of the busted hole. Combine that with closing off the open hole, and it should be pretty effective.

What about the time that would take to make a new hole? A month?

 

[mgb_phys]

If only they could contain and capture the mess. Maybe that ability should be a requirement before drilling.

It is and they can, the leak is producing about 1000 bbl/day and they have skimming capacity for about 100x that much (http://www.rigzone.com/news/article.asp?a_id=91509)
Offshore you try and collect the oil with floating booms and then skim it off the surface and back into barges then tankers, especially with light crude. Spraying detergent makes the oil break up but it also disperses into the water where it gets into the food chain. Although the slicks on the surface look bad (and are for any sea birds) it's the best place to deal with it.

Then again, isn't there some type of "safety collar" that the drilling pipes slip through that could stop the flow during a drilling emergency?

The reports are that a well head was in place but was damaged in the blast, they have ROVs trying to close it.
If that doesn't work you can pour concrete and try and block it - that makes it a bit of a pain to reopen the well - especially in water this deep.

 

[russ_watters]

Offshore drilling is much safer than it used to be, it is argued. While that may be true, the claim falls flat considering the oil spill still in progress, in the Gulf of Mexico. [snip - separate posts]

I thought these things were supposed to have a failsafe at the source to stop the flow in the event of an emergency. So much for that promise. It doesn't work.

Once again, I feel we have been lied to by industry.

Since this is an unreferenced claim of fact, to avoid this whole thread just being a strawman-based rant of you against an imaginary opponent, please cite the source of your claim. Who told you "these things were supposed to have a failsafe..." Who do you think lied to you? What, exactly was the lie?

Now we can probably work around that, because lies or not, it appears obvious that your point is that these things should be failsafe. So let's go with that - no lies, just your opinion.

Ivan, your opinion is just absurd. It is the same card-stacking propaganda technique so-called "environmentalists" use to (successfully) torpedo nuclear power. Here's how it works:

-First, you set an absurdly high bar as your criterion for dividing "good" and "bad". In this case, absolute perfection is "safe" and anything less than absolute perfection is "unsafe".
-Next, when the thing you are attacking fails to live up to the absurd criteria, you claim it is now by definition "bad". (unsafe)

So no, Ivan, it is not anywhere close to reasonable to demand absolute perfection from the oil industry regarding spills. "Reasonable" is to do a cost-benefit analysis of an industry's safety and determine from that what a reasonable failure rate should be. With the type of accident we're dealing with here, can you think of another case of this happening? I can't. That make for an extremely high level of reliability. If once every decade or two, we get a spill like this, that is a reasonable cost for such a critical driver of modern life.

Algae to the rescue
https://www.physicsforums.com/showthread.php?t=211274

What is that, spam? It's completely irrelevant to this thread.

 

[russ_watters]

For some perspective on the magnitude of this disaster, USA Today's article says it is spilling about 42,000 gallons a day. According to wiki, the Exxon Valdez, in 1984, spilled at least 10.8 million. The Valdez is perhaps the most famous, which is why it is cited in some of the articles about this. So anyway, if it keeps going at close to current rate for a total of a month, it'll spill about 1/8th what the Valdez did.

...and the Exxon Valdez doesn't make the list of the 10 largest in history, coming in 33rd at 1/4 the requirement to make the list: http://envirowonk.com/content/view/68/1/ So based on that, it looks like we get an average of about one such spill worldwide every year - not from drilling, specifically, but from the oil industry in general.

 

[Cyrus]

A data point is not a trend, Ivan. There were multiple car accidents today throughout the country, but I thought by now that auto makers told us for years cars were safe!

 

[drankin]

For some perspective on the magnitude of this disaster, USA Today's article says it is spilling about 42,000 gallons a day. According to wiki, the Exxon Valdez, in 1984, spilled at least 10.8 million. The Valdez is perhaps the most famous, which is why it is cited in some of the articles about this. So anyway, if it keeps going at close to current rate for a total of a month, it'll spill about 1/8th what the Valdez did.

...and the Exxon Valdez doesn't make the list of the 10 largest in history, coming in 33rd at 1/4 the requirement to make the list: http://envirowonk.com/content/view/68/1/ So based on that, it looks like we get an average of about one such spill worldwide every year - not from drilling, specifically, but from the oil industry in general.

At this rate it will take around 8 1/2 mo to equal Valdez. But, who/what really lives in Valdez? Not much.

This has more of an impact because of the abundance of habitation available to impact. Once it hits the coastline (subtracting media hype) I suspect it will be more of a mess.

I want offshore drilling but the loss of life and the mess is really f'd up.

 

[russ_watters]

Valdez is the name of the ship, not the location of the spill: http://en.wikipedia.org/wiki/Exxon_Valdez

 

[zomgwtf]

At this rate it will take around 8 1/2 mo to equal Valdez. But, who/what really lives in Valdez? Not much.

Lol well, Valdez isn't a place, it's the ships name. So that tid bit is wrong. Next up is that you assume that somehow the Valdez oil spill wasn't damaging to the wildlife... wrong again, the Valdez incident is often cited as one of the worst ecological disasters in USA history...

EDIT:
Saw russ posted on the next page.

Valdez is the name of the ship, not the location of the spill: http://en.wikipedia.org/wiki/Exxon_Valdez

 

[drankin]

Valdez is the name of the ship, not the location of the spill: http://en.wikipedia.org/wiki/Exxon_Valdez

LOL, I realized that this morning. That's what I get for posting late after a few. I should have a breathalizer on my keyboard. doh

zomgwtf, Valdez is a place.

 

[mheslep]

Photo of a deep water robot arm attempting to activate the blow-out preventer at the Deepwater Horizon well head site. Note the depth.

DH BOP here, apparently prior to installation.

Random BOP. Must be 500 tons. I'm baffled as to how these things are positioned and installed in miles deep water.

 

[mheslep]

More http://www.guardian.co.uk/environment/2010/apr/26/deepwater-horizon-spill-underwater-robots" context:

The last spill from an oil rig in the Gulf of Mexico of similar magnitude took more than 10 months to contain, said Dagmar Schmidt Etkin, president of Environmental Research Consulting. But that was more than 40 years ago, and technology has advanced since then.

 

[mgb_phys]

Random BOP. Must be 500 tons. I'm baffled as to how these things are positioned and installed in miles deep water.

ROVs and people who are really good at Video games!

Even just drilling is tricky. Rigs in water this deep aren't anchored - they are just floating on the surface with a mile long drill bit going down to the seabed. Although the drill string is something like 30" in diameter on these scales it's like drilling with a 6ft long bit of wet spaghetti.

 

[MotoH]

ROVs and people who are really good at Video games!

Even just drilling is tricky. Rigs in water this deep aren't anchored - they are just floating on the surface with a mile long drill bit going down to the seabed. Although the drill string is something like 30" in diameter on these scales it's like drilling with a 6ft long bit of wet spaghetti.

I am almost positive this was a SPAR rig. Those work in up to 8k feet of water, and they are anchored.

The unanchored ones are oil ships.

 

[mheslep]

ROVs and people who are really good at Video games!

Still, there's no getting around the fact that the surface rig must still have a 500+ ton crane and a mile of 500 ton rate cable underneath it.

Even just drilling is tricky. Rigs in water this deep aren't anchored - they are just floating on the surface with a mile long drill bit going down to the seabed. Although the drill string is something like 30" in diameter on these scales it's like drilling with a 6ft long bit of wet spaghetti.

I know. I've always been curious though to known what happens in the occasional position holding outage, or even a large sea state of +/- 20M. There must be some kind of length flex built-in to the drill string.

 

[Al68]

Recently we have seen a push by Obama, as well as long-time proponents, to increase offshore oil drilling. Offshore drilling is much safer than it used to be, it is argued. While that may be true, the claim falls flat considering the oil spill still in progress, in the Gulf of Mexico. This isn't making me a believer! Right now, one expert on CNN is saying that we don't know exactly how it will be stopped. It could weeks or even months! Once again, I feel we have been lied to by industry.

Nice bait and switch. First, mention a claim made by Obama and others that you can't disprove. Then imply a different claim that nobody made (strawman). Show the strawman claim to be false and pretend the people who made the actual original claim must have lied.

And of course you know this is just another nonsensical hateful troll post. No human is stupid enough to write such a post innocently not realizing how absurd it is.

 

[mgb_phys]

Still, there's no getting around the fact that the surface rig must still have a 500+ ton crane and a mile of 500 ton rate cable underneath it.

The drill string weighs a lot more than that, these sort of rigs can drill 10,000ft deep holes with a drill string 24-30" diameter. 500tons is nothing.

I've always been curious though to known what happens in the occasional position holding outage, or even a large sea state of +/- 20M. There must be some kind of length flex built-in to the drill string.

There is a lot of flex in the drill, that's the problem!
This was drilling in almost 5000' of water with a 21" diameter string - to scale that's like a human hair 18" long.

 

[MotoH]

The DPSS drills are very stable though, from what I have read and have saw. The blowout at the base caused the fire, not because the drill moved (unless that isn't what we are talking about)

 

[mheslep]

The drill string weighs a lot more than that, these sort of rigs can drill 10,000ft deep holes with a drill string 24-30" diameter. 500tons is nothing.

But that weight is partially supported by the drill piping in the sea bed. A BOP has to all be carried by tension transferred by cable to a crane on the rig.

There is a lot of flex in the drill, that's the problem!
This was drilling in almost 5000' of water with a 21" diameter string - to scale that's like a human hair 18" long.

Lateral, sure, not longitudinal.

 

[mgb_phys]

Lateral, sure, not longitudinal.

The rig sits on a couple of very large submerged pontoons, in moderate sea states the height of the waves at the surface isn't an issue, the rig stays at the same average submerged depth.

In 'interesting' sea states you stop drilling and disconnect the drill string from the rotary table - a crane holds the top of the string and reels cable in and out to keep a constant tension on the string as the height of the rig changes.

 

[edward]

Ironically what ever happened did so in calm water. The Deepwater Horizon had the latest GPS dynamic positioning equipment available. It was installed starting in in 2000 at the time the rig was built in Korea.

http://www.dynamic-positioning.com/dp2000/power_foss.pdf

The diagrams in the pdf looks like there are eight generators for eight positioning thrusters. All GPS and computer controlled. What could possibly go wrong?? Bolts break, pipes crack, human error. There are a lot of low tech problems that can undo the best technology.

The latest drill ship the, West Polaris, was also built in Korea. This was the one Cheney claimed was drilling off of the coast of Cuba.


Perhaps we should consider having the Koreans install the latest technology in the oil recovery and skimmer ships?

 

[mheslep]

In 'interesting' sea states you stop drilling and disconnect the drill string from the rotary table - a crane holds the top of the string and reels cable in and out to keep a constant tension on the string as the height of the rig changes.

Ah. Thanks, makes sense.

 

[mheslep]

Ironically what ever happened did so in calm water. The Deepwater Horizon had the latest GPS dynamic positioning equipment available. It was installed starting in in 2000 at the time the rig was built in Korea.

http://www.dynamic-positioning.com/dp2000/power_foss.pdf

The diagrams in the pdf looks like there are eight generators for eight positioning thrusters. All GPS and computer controlled. What could possibly go wrong?? Bolts break, pipes crack, human error. There are a lot of low tech problems that can undo the best technology.

Do we know that loss of position keeping was the proximate cause of the catastrophe? Could have been any number of other things I expect. Explosion/fire?

 

[MotoH]

The explosion was most likely caused by blowout. Pressure from natural gas and other gasses can build up and will expand when the riser is brought back to the surface. When the gas expands it can ignite if not vented properly. Which seems to be the case for the Horizon rig.

 

[calculusrocks]

Just sayin'... if the oceans were private property instead of common property, then there would be injured parties that would have to be compensated. There is no incentive to take good care of common property, which is why they become potential dumping grounds. We have agriculture, why not aquaculture?

 

[MotoH]

Just sayin'... if the oceans were private property instead of common property, then there would be injured parties that would have to be compensated. There is no incentive to take good care of common property, which is why they become potential dumping grounds. We have agriculture, why not aquaculture?

You don't think BP is going to take care of the families involved? Come on now.