What’s really happening in the Gulf Oil Spill

I appreciate all of the concern with the disaster in the gulf, but there is an awful lot of ignorance concerning the mechanisms both on ATS as well as the myriad of so-called experts in the MSM. I am posting this thread, since I have been in the oil business for over 30 years working as a petroleum engineer and have actually designed drilled and operated oil & gas wells. This explanation may get too technical, but at least it will expose and dissipate myths concerning this disaster.

Any oil well is drilled starting with a large diameter that at certain points in the process the large diameter holes are cased off with pipe and cemented in place for various reasons and the drilling is continued with smaller diameters until it reaches its objective. I will not go into all of the reasons pipe is run and a smaller diameter is initiated, take my word for it happens & is necessary.

The Horizon Explorer had several strings of pipes until the final 7” pipe was run (probably the 7” was run in 9 5/8” OD casing). The well is blowing out of the annulus between the 7” casing & the 9 5/8” casing. There is no flow inside the 7”. This casing has tools & check valves that prevent anything from flowing into it. The 7” was supposed to be cemented in place, but the well was starting to blow out during this process. So the cement was being diluted with oil & gas where it could not solidify and shut off flow from the reservoir @ 18,000+/- feet below the seafloor.

I will not go into the failure of the blowout preventer. Let is suffice to say it didn’t work as designed and with the flow coming out, the oil & gas flowed up the riser (the pipe that connects the wellhead to the drilling rig) and it was game, set & match.

When the rig sank the riser was still attached to the wellhead and fell over & split in a reported 3 places. It w as reported that 16.5 #/gallon drilling mud was in the riser and the well blew out when it was replaced with seawater. To understand the physics I will try to explain hydrostatic head. The pressure created from a column of fluid in an oil well is identical to the reason you have water pressure out of the tap at the kitchen sink. Water which weighs 8.33 #/gallon is put into a water tower 100’ up in the air. Fresh water has a hydrostatic head equal to .433 psi per foot of height. Therefore you get 43.3 psi at your shower head. If water weighed 16 #/gallon then you would have 86.6 psi in the shower.
Similarly as an oil well is drilled there is a fluid known as “drilling mud” that is pumped into the drillpipe, through the drillbit & circulated back to the surface where it is screened to remove the soil dug out of the well. This “mud” is carefully monitored to make sure that if encounters oil or gas it is heavy enough to keep it from flowing into the wellbore. The well in question had to have 16.5 #/gallon mud weight to keep the oil & gas from flowing. The hydrostatic head of the mud of this weight as opposed to fresh water is .86 psi/ft. This means that the pressure in the oil reservoir encountered must be nearly 20,000 psi. ((18,000 + 5000) X .86). As the oil replaced the column of mud that would offset this bottomhole pressure it began flowing faster & faster into the annulus with more & more force as the weight of the 23,000 foot column of fluid became lighter & lighter. When the “company man” (the BP guy in charge) removed 16.5 #/gallon mud from the riser with 8.4 #.gallon sea water he immediately reduced the hydrostatic pressure 2000 psi & it was over.

Now BP is trying to recreate this heavy mud column to offset the bottomhole pressure to balance the well using the “top kill”. A “top kill” entails pumping weighted fluid into the top of the well and forcing the oil & gas back into the reservoir and filling the annular space with heavy mud creating a hydrostatic head equal to the reservoir pressure. The oil & gas are not flowing from a void in the earth it is flowing out of the tiny spaces between sand grains. There is a limit how fast the fluid will reverse & flow back into the formation sand. If the mud is pumped at a higher rate than the formation can absorb then the pressure increases and even the heavy mud may be inadequate to hold back the bottomhole pressure and when the pumps stop the mud starts flowing back. In addition, if the injection pressure gets too high it may exceed the burst strength of the casing in the well. If the casing splits & starts blowing out into the ocean bed the party is over, there is no way to control unless the flow in contained inside pipe. So the top kill is a precarious balancing act. To further complicate this situation it appears that 90% or more of the mud is not going down the hole, but is being spewed into the ocean. To get more down the hole one needs to pump at higher pressure which means increased rate which means more escapes instead of going down creating increased hydrostatic head to decrease the flow from the reservoir. The junk shot (rubber, golf balls, etc) is not to solve the whole problem; it is only to try to reduce the amount of mud that is escaping from the holes in the riser. They shut down periodically, to measure pressure to estimate how much is going down the hole & how much is being wasted. If the well initially flowed at 5000 psi & after a day of the “top kill” it’s flowing at 4000 psi then we have offset 1000 psi of the oil & gas with mud. If the mud weighs 16.5 #/gallon with a hydrostatic head of .86 psi/ft then we have successfully gotten 1200’ of mud column in the well if we assume only gas in the wellbore. It’s actually not this much. Having done “top kills” on land with varying degrees of success I can assure that its not easy under any circumstances much less those out here.

A “bottom kill” is vastly easier and is what the relief wells are about. Unfortunately for that to work the relief well must intersect an 8 ¾” diameter well bore 3 miles underground in the dark. It has been and can be done, but the deep intersection is necessary so that the enormous bottomhole reservoir pressure can be offset with heavy drilling fluid. The drilling mud will then displace the oil and gas from the bottom rather than try to force somewhere it doesn’t want to go. Once the heavy fluid balances the bottomhole pressure then cement can be put into place that once set up will end the need for the heavy fluid.

I apologize for the length of this post, but there is no shorter way to correct all of the misinformation.

Your post is very informative. Thanks for sharing!
I am also curious as to what info you think is wrong or misunderstood.
From your post, it seems that you are not hopeful of the outcome.
Do you think that either image from BP is the "real" oil spill site?
BP is saying that whatever the live feed show, don't make any assumptions about the progress of the "kill." Is that realistic?
Can it really be working without any obvious abatement of the flow?
Thanks

They are considering chopping it off at the riser..What are your thoughts on that?
Does a clean hole make a better chance of success?

So in other words what????

I have no idea what the message was in there....

We were screwed from the start??

They could have stopped it right away???

It could only run it's course to stop??

I really have no idea what was just said there....

Common folk english please!

President Obama said he has been on top of this since day one. Everything BP has done has gone through him and the government. I for one believe him. After all he had to take his lasar focus of the economy and place it somewhere. Unemployment is around 10% so the President's laser focus has to be on something else right....

The leak needs careful planning when it comes to being resolved. One small mistake could lead to an explosion resulting in many other leaks. That's why it's taking such an extensive process to fix this mess we're in. You can't just go down there and mess with things you don't know. In fact, this is a "learn as you go" process. No one knows what will happen...not even the experts as none of us really dealt with this before.

Thank you for the great explanation! It seems like you and BP have known what to do from the start to fix the leak. Why is BP taking their sweet a$$ time? Maybe, you should get in touch with the President and BP to fix the leak, and become a national hero!

Do you think the "Top Kill" method will be successful?

Why did BP take so long to attempt the "Top Kill" method, and in your opinion why hasn't this leak been fixed already?

Doesn't 40+ days seem a bit too long to accomplish the task of pumping weighted drilling-fluid into the well to equalize the pressure, even if must of it is getting sprayed back into the ocean?



[edit on 29-5-2010 by tooo many pills]

Great post,OP, thanks for this indeed needed piece of clarification. I read a Dutch oilexpert saying BP made the mistake, as the one managing the rig and not responding to nasty 'pressure data'.

Circumstances seem to be very difficult. How do you look at this ecological disaster, compared with what you know of other blow outs in the world, and the way they handled it?

Do you have a gallon opinion?

Somewhere else on the forum it was mentioned the Russians did nuke blow outs, a number of times, 7, if i'm correct. I wouldn't be surprised but I'm curious after your opinion on that one.

Thanks!

[edit on 29-5-2010 by Spinoza73]

Many thanks for an informative post. This posting is a sincere request for intervention.

I take from the post that a "bottom kill" is the only conventional fix at this stage. Barring other ideas that I do not have the understanding to properly assess. For instance, if say the nuke is being bandied about as an option, we really need to hear from a nuclear engineer the realities of that also, ie exploding a device at such depth and temperature, after affects - my gut instinct is that its another timewaster but I am no expert, just common sense aversion to the clumsy technology and aggressive mindset behind its creation puts it in a similar category as chemotherapy for cancer, too many movies make the nuke the magic solution to planetary solutions, like "the core".

We are given a time frame of a few months for "bottom kill". Is this realistic or another PR "best case" scenario? What about weather conditions, unforeseen difficulties at this depth, hurricane season. Is there a comparable situation of "bottom Kill" from the past that could help us relate.

At a few weeks in, we have a massive scenario on our hands. After a couple more months, what size plumes and surface area are we looking at? Fumes, rainfall on land, the ocean as a whole, the food chain? How about after 4 months? What if it takes 6 months? Or a year or longer? Surely these are reasonable questions?

Perhaps it gets to a certain point and certain other parties are forced to intervene; we know that there is a lot of observation of Earth going on at this time due to the mass of eyewitness testimony such as on 'filers files'. Or even our own secret technologies capable of withstanding and working in outer space and tunneling at great depths can surely be leveraged to work on the ocean floor.

If there is a quick fix, I believe it will be such intervention that occurs and would be a suitable cover story. I actually believe humanity has the technology but it is in the realm of 'suppressed technology.' The alternative as I understand it is the "bottom kill" option that takes anything from 3 months to 2 years, cascading us in the meantime into a downward spiral of other events also.

Therefore I repeat my request for intervention to occur within the next few weeks.

they are now bringing in another riser that will clamp on to the top of the BOP.

Originally posted by Iamonlyhuman

1b.) If not, why hasn't BP initiated the bottom kill? And, how long will it take for the relief wells intersecting the well bore to be accomplished?

Not that I am any expert, but I think a relief well was started right away, it just takes a LONG time to get it and the equipment in place and drilled down 5,000 feet. It's not like BP is just now starting to drill the relief wells. I would imagine they have multiple relief wells being drilled, as it sounds pretty hard to "hit the bullseye" of the original well.