DeepWater Horizon-- Digging for Facts

Various --- Oil Drum initially ^ | June 21, 2010 | Ernest at the Beach

[Ernest_at_the_Beach]

An attempt to look thru various sources and answer some basic questions .

1. Can we get a handle on a basic Fact ...What was the pressure at the bottom of the drilled hole in the formation ?

From the Oil Drum:

BP's Deepwater Oil Spill - Matt Simmons on Dylan Ratigan Today, Closing the Relief Ports, and Open Thread 2
Comment by avonaltendorf on June 8, 2010 - 12:06am

Thread Posted by Prof. Goose on June 7, 2010 - 9:00am

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Comment by avonaltendorf on June 8, 2010 - 12:06am

I received a personal note, which I acknowledge gratefully.

Down to business. I agree with Matt Simmons and posted as much evidence as I could garner from publically available ROV feeds. We aren't being shown the IR or sonar images. Low res video is crap compared to what the ROV pilots and BP folks are looking at. Obviously USCG is in the dark or has been ordered to follow the White House playbook until they get a handle on how big a problem they have. In my view, it is a medium-sized problem, not quite as gigantic as Simmons suggested to Ratigan.

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Let's roll the movie back to the events of April 20. Simmons thinks that the reservoir pressure is 30,000 psi judging by the force of the blowout. This is clearly impossible. If true, it would have blown out immediately on penetration April 17. The scout ticket tells us that the pressure at the top of the reservoir was no greater than ~13,000 psi based on mud weight to control lost circulation:

LWD (RLL, BATSON, PWD) @17173, M 14.1, NO SWC, 9 7/8 LNR @14759-17168, LOT 15.9, LWD (RLL, BATSON, GEOTAP, PWD) @18260, LOST CIRC W/14.4 MUD, C&C SPTTD LCM

LWD=Logging While Drilling
RLL=Recorded Lithology Log with gamma ray and resistivity
NO SWC=No Side Wall Cores

PWD=Pressure While Drilling
LOT=Leak Off Test to measure strength of wellbore wall

At 18260 ft, Lost Circulation with 14.4 lb/gal mud, then Circulated and Conditioned the mud and Spotted a Lost Circulation Material pill to cure the losses. They had drilled into the top of the reservoir (gas cap) and mud started leaking away into the reservoir, because 14.4 mud weight was greater than the reservoir pressure. Assuming a vertical well, reservoir pressure was less than 14.4 x .052 x 18260 = 13768 psi, or mud would not have been lost.

It was a slow process of gas reaching bubble point plus a nonsense negative test ordered by Kaluza that sandbagged the drillers into displacing to seawater without watching mud returns or understanding what was happening. When a gas bubble formed it expanded rapidly as it travelled up the riser unopposed, blowing out the seawater and mud. It was followed by very light liquid and more gas. The BOP did not fire on EDS from the bridge because hydraulics were gone or malfunctioned, but there was mux control to one or both of the pods. Only when the rig sank and riser collapsed did the BOP see a "deadman" condition and attempt to shear the drill pipe -- except by then it was clogged with debris and couldn't shear or close fully.

Thus we have gas and light oil at low pressure spewing from the riser swivel. Below the BOP should be ~8,000 psi, which is sufficient to find paths of opportunity to nearby vents. However we have to keep in mind that collapsed casing and broken cement gives the reservoir a path to salt welds (thin mostly vertical remnants of salt withdrawl) and fractured slump faults. It is therefore possible that light oil at 13,000 psi could migrate updip miles away.

I posted such evidence as I found. It is not enough to prove anything, but convinced me that Simmons knows the deepwater GoM geology.

[Ernest_at_the_Beach]

Thanks,,,...there is a whole industry out there spamming with horror stories.

See that last link at #37.

[Ernest_at_the_Beach]

One question at a time...

I have been wondering, how did the blowout preventer fail?

Based on what I have read at The Oil Drum....there is much discussion that there seem to be two driss strings that showed up in the riser....

If so the shears would have had a problem.

I am not prepared to chase down the subthread area where that got discussed....believe it had a photo.

[Ernest_at_the_Beach]

two drill strings

[justa-hairyape]

Saw a comment on the Oil Drum that sometimes when the drill pipe gets sent upward due to a blowout, it can break at points. Where it breaks there can be and area where the broken pipe gets pushed up around the other section it broke free from. So two drill strings could be one that was broken in two and overlapped due to the incredible forces of a blowout. At any rate, if the shears did fire and fail to completely close the pipe, the main pipe above the wellhead within the BOP has a compromised integrity.

[Marine_Uncle]

I have been watching the twelve ROV's at work for a number of hours. And they are very busy putting in by what looks like new control panels into the BOP, manifold sections, rearranging piping, moving about the various sea floor units installing what could be pressure valves, turning valves etc.. And of course seeing the new cap waiting to be installed.
The ROV that was working on the BOP's control panels after completing it's work backed off moved about the sea floor slowly. There was no sign of any leakage, depressions around the bottom of the BOP where it meets the main pipe coming out of the sea floor. And the BOP looks pretty damn verticle to me. I have grown weary of all the horror stories and misconceptions that are floating about the Internet.
Real time pictures speak volumes. The BOP is not leaning and the seafloor bed is normal looking. No fissures. And it sure looks like they are going to be ready to soon install the new cap system in place.

[Marine_Uncle]

Gondring:
Pulling their leg is putting it mildly. There is so much bull shit circulating about the Internet regarding the spill I am fast reaching a point where I am going to just ignore the crap and watch the increased activities by the twelve ROVs.
As far as I am can see, BP is working around the clock to get every last little thing in place in order to cap the well shortly.
And one can with an honest mind discuss why they where not allowed to reach this point way sooner, but the point is they may soon effectively install a leak proof cap and simply pump oil and gas to the surface vessels in the remaining days before the final dead kill is performed.
There will be plenty of time for debate once the final verdicts are shown as to who screwed the pooch.
But since the cat is out of the bag.....Happy Birthday Ernest. May the good Lord give you many healthy ones to yet be.

[GGpaX4DumpedTea]

I have some methylene chloride. It is safe to use. I use it on occasion to ‘weld’ acrylic (Plexiglas). It welds by putting a thin film on each part into solution, then when the methylene chloride vaporizes the parts are ‘welded’ together - a very strong bond.

[GGpaX4DumpedTea]

Methylene chloride, by the way is a liquid, as is benzene. Of course, both vaporize, and can be in a gaseous phase. The benzene, H2S and methylene chloride gases would disapate quickly and be at non-hazardous levels in a very short time.

[Cold Heat]

No, the casing is quite intact, and all this crap is just crap. I concur with all you said, however it has been many years, 1979-85 since I worked in the gulf. I left to do maintenance on land because i was tired of throwing welding rods at seagulls.

[Cold Heat]

What do you think about the ROV's video capabilities. It's all 2D, and makes it really difficult for them to have any sort of depth perception in 2-D. We have had 3-D camera's for some time and even 3-D rendering from stereoscopic camera setups.

They waste so much time without depth perception and that could be fixed for a fee that is.....LOL

[Marine_Uncle]

Cold. Heheh. The only welding rods I had in my hands way back where those used in small time brazing... I did in my home shop and with my bro with a arc welder to fix my fire place grid. LOL.
On a serious note. I noticed some post by you also in the past few weeks where you entered some very reasonable statements. Due to the often short times I post and work schedules I did not back you up.
As for the 3D camera question. I am sure it could help the operators in their daily manipulation of the ROVs. A note if I may. As I have watched over the past few months the many ROV activities. In my case at least, I seem to be able to calculate how many inches for instance the end of a ROV hand finger may be away from some restricted area say where they are trying to push a small cigar size pressure sensor or other thing into a panel hole, etc..
It is like the more one carefully watches the many functions being performed by these ROVs' over time they train their eyes to sense just where the arms, and fingers of the robots are honing into etc..
I fully agree with you that if they do not at present have multi-views as the bots do their work it would be a blessing to them and cut down on many hours per day for the routine things these bots are doing. And of course cause less frustration amoung the ROV operators.
A last note. I wonder if sometimes they are just practicing their trade. Which I don't have a problem with. Hone ones skills so they don't FU when critical connections in hard places is required.
Lets consider this however. How much more the probablity of two close working ROVs exists to provide at three dimensional view in often tight quarters, to perhaps cause an accident between the two ROVs or damage equipment they are working on in very tight quarters. I watched tonight as a ROV using it's two hands carefully had to insert a rather small object (about the size of a cigar...perhaps some kind of release valve) into a small opening in one of the lower BOP's control panels. It took probably five minutes or so to finally insert the object into the panel control, where inches away there was a open cage containing cylinders looking to be about two or three inches in diameter and some two feet long. The cage was getting in the way, so that the bot hand could not properly line up above the hole in the control panel to insert the cigar object.... maybe it was a Havana Cigar disguised as some pressure relieve valve....
In that case. If another ROV was ninety degrees to the right centered on the control panel area, it would not have helped the main bot's arm from zeroing on the Z axis to insert the cigar shaped object. The bot's hand had to place the Havana Cigar into the other hand of the bot momentarily until it could move the cage backward a bit, then transfer the cigar back to the right bot's hand then insert it into the hole in the panel.
So perhaps in some cases your good suggestion simply would not apply. But it is noteworthy. And perhaps in the future shall be a standard procedure.
Why not provide side cameras on flexible arms to accomplish what you suggested.
Bottom line. I appreciate your observances regarding 3D camera operations.

[Cold Heat]

Thanks for the words.

Yeah, I have noticed a good bit of "on the job training" going on with some operators. I am sure operating these things 24/7 has caused a bit of a personnel issue with experienced people.

One thing to note, these ROVs are huge machines. I have seen them work in tandem but they do it across from each other and I am sure they do it to share the views from the cameras to determine positions of tools etc. It gives them at least a better sense of depth. A stereo camera would not have any effect on the bots size or maneuverability. Its just two cameras rather that one that operate in tandem. The two camera views are from different angles and they are rendered by a computer to form a picture that has depth as well as the the two other dimensions of length and width. You would likely benefit by wearing video goggles or glasses as opposed to a screen, but they have recently started marketing 3-D screens as well. With this feature, they would not miss the cigar sized hole unless the ROV moved due to currents. Rather that ten attempts, they could do it it two. That is what I saw anyway...

Yes, I was getting pretty good with those seagulls. I hate to kill something that I don't eat however so I stopped doing it.:-)

[Marine_Uncle]

I'm with you on your suggestions. as well as observations which you observed. 3D views obviously would let them zero in quickly on what must be done, instead of playing hit and miss. Your right 100% period.
On a side note.
For many years I used to do catch and release trout, bass, and other pan fish on rivers, streams, lakes etc.. Never killed a fish. Gently released them. The good Lord provides us with food as required. I can imagine however how you at one time felt it required to belt a few of his noble birds to get the hell out of the way.

[Cold Heat]

Well, it was more to see if I could do it, and then I had to prove it from time to time when others asked me about it. This was back in the old days. They forbid it now because it became a popular sport. Not to mention the expensive welding rods.

But you and I do have the no killing thing in common. I quit hunting 20 years ago. Still have most of my guns, but I keep them for another purpose now.

I discovered that hunting a defenseless animal made me sad and I quit.

[CharlesWayneCT]

From what I understand they have had to build this new cap pretty much from scratch, designed to handle the cold, based on the lessons they learned first from the failed “big box” fix, and the current cap.

in fact, they were originally going to get this new cap in place I thought right at the start of the month; my GUESS is that the failure they had last week when the rover ran into the hose has caused them to make some sort of design change — I don’t know this, maybe it’s just taking longer than expected.

As to why it took so long, ignoring the interference of our government, my guess is that at the start they didn’t really know they had such a problem, and they didn’t really understand that their traditional methods wouldn’t work. I think they were pretty sure dropping that big box on the well was going to stop the leaking, so they hadn’t put a lot of effort into any special caps (which at the time they couldn’t use because the pipe was still attached).

[CharlesWayneCT]

I don’t know if they have 3-d capabilities. But they have much better sensors than what we see. We are seeing a reduced-bandwidth visual feed. They also have heat and infrared, and a much higher quality video.

[mad_as_he$$]

You should try Chukar hunting if you think animals are defenseless.

[Cold Heat]

I'd like to think that, but I viewed a piece of vid taken in the control room of the primary recovery ship, and as they looked over the shoulder of one of the operators and his joy sticks, I discovered to my surprise that he was looking at the same vid picture that I was seeing. He had other views from a second camera and views from a second bot, but other than the ability to zoom in, I did not see anything different.

I don't doubt the infrared capability, but you really can't see a lot of detail with that to help with anything they were doing at the time.

I saw a lot of higher tech stuff in regard to the attachments, but I felt the video was lacking and a bit behind the curve.

The Skandi bots have the best video but they were being used for monitoring and dispersant's. Their vid was high definition and also had computer enhancements or filters. But, the enhanced vid is not what the eye would see and makes the picture look a bit distorted and the colors and texture are way off.

[Cold Heat]

I went pig hunting with a sharp stick once with a couple of South Louisiana Coonassses. It was fun, but those guys are just about crazy....LOL

[mad_as_he$$]

lol..

http://iron-horse.us/chukar/where_to_find_chukar.shtml