Oil Pressure Stopping Short of Target ... Does that Mean the Well Integrity Test Is Failing?

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The well integrity test is arguably failing, as the pressures are not
reaching the 8,000 psi minimum
target.

CBS News notes:

The
federal pointman for the BP oil spill says results are short of ideal
in the new cap but the oil will stay shut in for another 6 hours at
least.

Retired Coast Guard Adm. Thad Allen said on a Friday
afternoon conference that pressure readings from the cap have not
reached the level that would show there are no other leaks in the well.

He
said the test will go ahead for another 6-hour period before being
reassessed to see if BP needs to reopen the cap and let oil spill out
again.

MSNBC writes:

Allen said two possible reasons were being debated by
scientists: The
reservoir that is the source of the oil could be running lower than
expected three months into the spill. Or there could be an undiscovered
leak somewhere down in the well.

The New York Times reports:

Thad W. Allen, the retired Coast Guard admiral who
is overseeing the response to the gulf oil spill, said that while there
were indications from the test that the well was in good shape, it was
not yet possible to rule out damage that could complicate efforts to
halt the leak permanently.

“We want to be careful not to do
any harm or create a situation that could not be reversed,” he said in a
conference call with reporters Friday afternoon.

***

Admiral Allen said the test would continue in six-hour increments and
that any new data would be reviewed by scientists and engineers from the
government, BP and other companies. He said there would be “enhanced
monitoring” of the seabed, including acoustic tests that could detect
tiny bubbles of methane gas coming from the bed, which would be evidence
of damage to the well.

***

Admiral Allen said that such
a pressure buildup suggested that the well was not damaged. But he
said that the pressure level reached — about 6,700 pounds per square
inch, or more than 450 times atmospheric pressure — was below that
expected for an intact well.

One explanation for the ambiguity,
he said, is that the reservoir of oil 13,000 feet below the seabed
could have been depleted by the well as it galloped out of control for
nearly three months. But another possibility is that the well is
breached, with oil and gas escaping into the rock or, worse, into the
gulf through the sea floor.

BP states
that the pressure in the well is only rising 2 pounds per square inch
each hour.

I will post a transcript of Allen's report when it becomes available (here is an unofficial, rough transcript).   In the meantime, blogger Wang - who attended the press conference by
telephone - added
details from Allen's press conference (I simply edited for clarity of
reading; I will update with corrected and expanded transcript as I
receive it):

Uncertainty about the meaning of the pressure. Could
be lower because of well integrity, or the reservoir has become
somewhat depleted and so is lower in pressure than expected.

The
initial curve of pressure build up was normal but stopped short of our
target which is the concern.

Don't want to create harm or an
irreversible situation.

Was the reservoir depleted or is there an
ongoing way for the oil to leave the well bore? We do not know the
condition of the well bore. There's a good chance it could be
depletion. Checking out the well bore. Checking for leaks. We have no
indication of a seafloor breach so it could be reservoir depletion.

Additional seismic surveys are required.

This kind of formation
can maybe heal itself if we do damage it, the quickest way to reduce
pressure is opening the kill and choke line.If there is a problem we
will vent the oil.

Reservoir depletion can be measured by
determining if there was an aquifer beneath the reservoir but there is
not one. If the seismic and acoustic show no sign of leakage we will
continue with the testing.

NOAA boat looking for methane from the
sea floor with acoustic device. There is some concern about methane.
We want to make sure there is no methane. If we were to detect
methane we would lower the pressure by venting or ramp up Helix
Producer.

We will reevaluate in 6 hours and have a series of
meetings (with the committee) everything moving forward is condition
based. We should have results in the next 6 hours. The 6 hour period
starts now.

There are actually at least four potential explanations for the low pressure
readings:

(1) There are substantial
leaks in the well;

(2) There is leakage in the sands deep
under the seafloor. Oil industry professionals posting at the Oil Drum hypothesize:

What this could indicate is that there is a
possibility of crossflow at the bottom of the well. What this
means that the oil and gas that are flowing out of the reservoir into
the bottom of the well, are, under the pressure in the well, now flowing
into a higher reservoir of rock, now that they can't get out of the
well. Depending on where that re-injection flow is, this may, or may
not, suggest that the casing has lost integrity. This is a topic that
has been covered in the comments at The Oil Drum, where fdoleza -
"a petroleum engineering consultant retired from a major
multi-national oil company" - has noted:

... I
believe the flow will be coming out of the bottom sand and going into
the upper sand. It would not be a leak, but it would tell them why
their pressure data ain't a classical surface buildup. And I sure hope
they're modeling temperatures and so on, because this is a very
interesting case. They don't have downhole gauges, so they'll have to
take the way the oil cools down as it sits to get a better idea of the
way things are moving down below.

If there are
questions whether there is still flow in the formation or from the
original formation into surrounding rock, then it is possible that the
relief well (RW) is close enough to the original well (WW) that
putting a set of very sensitive microphones down the RW might allow
some triangulation to estimate where such a flow might be occurring.
It might make it easier that the well hasn’t been finally cased yet.
But the test has 2 days to run, and will be evaluated every 6 hours.
With time some of these questions may be answered as the test
continues. (If there is no flow anywhere, after a while all the
readings should become quite stable).

(3) A
hypothesis proposed
by Roger N. Anderson - professor of marine geology and geophysics at
Columbia University - that the pressure could be rising slowly not
because of a leak, but because of some kind of blockage in the well:
"If it's rising slowly, that means the pipe's integrity's still there.
It's just getting around obstacles"

or

(4) The reservoir
has been depleted more than engineers anticipated (although many experts
have said that the reservoir is much
bigger than BP has forecast; in any event, there are factors other
than size which determine pressure. For example, blowouts can reduce
pressure pretty quickly in some reservoirs)

While many oil industry experts are betting on damage to the well
bore or communication between layers of sand, Don Van Nieuwenhuise -
Director of the Professional Geoscience Programs at the University of
Houston - thinks
reservoir pressure has simply "deflated", and that 6,700 psi isn't
unexpected:

The
6,700 pound- per-square inch pressure reading logged inside the
blown-out Macondo well this morning may suggest that the well has lost
power over the almost three-month-long period it has flowed into the
Gulf of Mexico and not that the well is leaking somewhere beneath the
sea floor, a geologist who has been following the gusher said.

The

reservoir could have "deflated" since it began leaking April 20,
reducing the amount of pressure it is capable of producing, said [Van
Nieuwenhuise].

***

But Van Nieuwenhuise said this
morning's 6,700 pounds per square inch reading should not cause worry.

"I

don't think it's a cause for immediate concern, because it could
reflect a natural loss of oil in the reservoir," Van Nieuwenhuise said.
"It's amazing that it has held its strength for as long as it has."

***

When

they first said this, I said if they can get to 7,000 (pounds per
square inch) that would be good," Van Nieuwenhuise said. "The 8,000 to
9,000 estimate reflects its initial pressure, but since it's been
bleeding so much, I'm not surprised it's at 7,000."

Note 1:
Because pressures are still rising
(if only 2 lbs per hour), it probably means that the well
integrity test hasn't caused any new leaks so far.

Note 2: Oil
industry expert Robert Cavner
notes that seismic testing isn't
as straightforward as it sounds:

Seismic puts
sound into the sea floor, and
measures the time it takes for those sound waves to return. Different
kinds of rocks reflect sound waves at certain velocities, or speeds.
By measuring the time it takes for the sound to return from a certain
depth of rock, geo-scientists can draw maps of the subsurface. Often
you can get an idea of the fluid within the pore space of rocks by the
way it returns sound waves. They ran a baseline survey a couple of
days ago, and will compare that data to the data that they'll get today
to see if anything has changed around the well to indicate fluid
movement. But, as one of my geologist friends of mine likes to say,
reading seismic for precise conclusions is often like trying to observe
airplanes flying overhead while lying on the bottom of a swimming
pool. It's difficult to draw definite conclusions, even using high
frequency seismic, but it will be another data point.

Comments

[Cognitive Dissonance]

I guess Jim_Rockford doesn't recognize humor when he trips over it. See the little smiley face at the end? That's the sign that Humor might be employed, though I guess for the humor impaired the <humor alert> tag should also be used.

BTW Jim boy, happy 1 year ZH anniversary, considering you've been registered here for exactly 1 year and 1 hour. We're so very glad you decide to pop in on ZH every few weeks and whip us loony tin-foil hat wearing crazies into line. We just couldn't get along without you. :>)

<HUMOR ALERT>

[Jim_Rockford]

Compulsion confirmed.

My birthday was a ways back as I was at www.zerohedge.blogspot.com until Tyler's controllers told him to move over here.

Does that resonate?

[Cognitive Dissonance]

"....until Tyler's controllers told him to move over here."

Careful Jim, the shiny side of that tin foil you're wearing seems to be on the wrong side. Or don't you hold yourself to the same standards you hold everyone else? Facts Jim, where are the facts?

[Jim_Rockford]

I agree with Blindman.  He knows where the missing drillpipe is I think.

[Cognitive Dissonance]

So you DO believe in conspiracy theories, in this case that Tyler and ZH are controlled by hidden entities.

Of course you do, just as long as the conspiracy theory agrees with your (or your controllers) world view. If it doesn't, you immediately disparage that person's belief or conspiracy theory as bunk and demand absolute proof, all the while slinging ad hominem attacks at that person or anyone else who might also support the person you're attacking.

Say it ain't so Jim, say it ain't so.

BTW, who's controlling Jim_Rockford? Maybe you and Tyler get your checks from the same source?

[wang]

On the subject of conspiracy and ZH I have a question. Do some of the contributors pay to be contributors? I am thinking of the contributors that run subscription sites such as madhedge and reggie not Leo, George, Bruce or CD.

[Cognitive Dissonance]

I can only speak for myself since there is no place where all the contributors gather to talk to each other and compare notes. I pay nothing to contribute and I doubt anyone else does. But that's just my opinion.

In fact I started here on ZH just like everyone else, leaving comments under articles. And that is still where I spend the majority of my time on ZH. Back in late October of 2009, I received an e-mail from Tyler asking me if I would like to become a contributor. After throwing cold water on my ego, I accepted.

I don't know how one becomes a contributor, though I've seen a few commenters say they asked and were turned down. I think Cheeky Bastard became a contributor the same way as I, but you should ask him to confirm.

[wang]

Thanks for responding and I was quite certain that a core group of contributors would not be paying but it seems to me that Reggie and Madhedge are constantly featured yet in my view their quality does not warrant such visibility and of course theirs are subscription sites and to be linked to a blog as popular as ZH could actually be  lucrative, I mean very lucrative. (but that's just my conspiratorial self speaking)

Any thoughts on what the outcome of the test 24 extension will be?  I suspect that there may be a little less confidence in the relief well solution and thus the importance of this.

[Cognitive Dissonance]

I think the "test" will be declared enough of a success tomorrow that there will be lots of smiling faces for the cameras, just in time for the Asian markets to open. I think they will say that they will continue to pull oil/gas out of the various kill and choke lines for processing on the surface to reduce pressure, but they won't be opening the vents again unless it's needed, thus no more oil will be "spilled" into the GOM.

Everyone will then live happily ever after and within a few days, the story will fall off the front page. Except that the millions living near the GOM will suffer for months and years and never be properly compensated. BP will be allowed to finish developing the field after capping the wells. After all, they have a big bill to pay. Which will be tied up in courts for 15 years.

[Jim_Rockford]

You left out the part where 10 years from now there will be millions of Americans who will have convinced themselves that the well blowout and the rig explosion were carried out by Bush/Cheney/Giuliani... and dare I say "HALLIBURTON" <gasp>.  Anomalies such as the missing "phantom drill pipe" will have some nefarious significance,  and youtube will be awash in soothsayers and alchemists with pretty videos and "experts" attesting to God knows what.

[CD]

No, of course not. The full details, data, transcripts, witness testimony, video, audio will be on full file with the Library of Congress, which will have built a new wing to house the exhibit, free to access for all citizens in person or online, disproving any such vile suspicions and suppositions beyond a shadow of a doubt. Because we live in a free society, right? Open society, transparent administration, and all that?

[Jim_Rockford]

So in the absence of complete transparency and free-flowing information, is it justified to throw logic and science out the window?  And if so, to what end?  If I was a ZH contributor, I might make an essay out of that.

Also, in my little prediciton above, I left out the part where anyone who will try to reason with a Macondo Truther will be shouted down as a BP/Govt.  shill.

[CD]

The argument is not with the science, I think (in the case of some, anyway). The issue is with the selective, manufactured pieces of information coming out of the process that sometimes do not compute. With the assumption that both parties in control of the information have done some very, very unsavory things in the past. Both have misrepresented or blocked access to (what later became objectively known to be) the truth, often for decades. Both have an immense stake in the public perception of the events. Congress allowed two Macondo managers to report sick instead of testifying at the beginning. Why aren't these people in custody, protective if nothing else? Or is this not a true NS event? And the list goes on. The wacky science is a symptom, not the cause of mistrust in the gov't . Just because you're paranoid doesn't mean they are not after you. Then again, if they are, perhaps you aren't, after all... 

[Jim_Rockford]

The argument is not with the science

You left out logic.

Isn't it logical to assume that BP will lie when necessary in order to limit their liability?  Isn't it logical to expect the Govt. will lie in order to obscure the fact that they failed to protect the Gulf and its citizens in spite of all of the regulatory oversight?  Isn't it logical to postulate that a human made an error and lost control of the well which resulted in a fire, explosion, and oil leaking into the Gulf?  Etc.

[CD]

I don't see where we disagree, except perhaps in that ever popular grey area between where each of us thinks .com and .gov would draw the line of how much to lie about what. And what if any the potential consequences of this could be, aside from the laying of the blame squarely  on the other parties.

Another way to look at it might be like this...

[wang]

you have nailed it, disaster over.  Even George is back to posting on economic stuff.

and more importantly

Victoria's Secret Store in NYC Hit by Bedbugs

http://www.cnbc.com/id/38282452

[Jim_Rockford]

Okay, it ain't so. 

Did you forget to put in your humor tags or are you trying to impress Blindman?

[Rotwang]

Audio (sonar) evaluation of the subbottom strata. Usually a subbottom sonar has an operating frequency in the 1-3 kHz range. This frequency provides for good attenuation characteristics in the water column, and some level of penetration into the stratified bottom layers. Usable depths of penetration into the solid stratifications is not likely to exceed 100 meters of usable analysis depth, and more likely into the 10-50 meter range. A audio (sonar) analysis through the bottom layers, of the supposed 13,000 feet is not possible with this technology. All you will access is the very top layer. Currently such sonograms will allow differentiation between sand, clay, rock etc. I am sceptical that attempting to analyse changes in the formation at any significant depth below the actual ocean bottom has any degree of success with this technology.

[wang]

here is the unofficial transcript of the BP briefing Saturday am

http://unixwiz.net/bp/tech-2010-07-17-am.txt

[wang]

Notwithstanding the collective wisdom of the industry veterans and assorted hangers on over at Oil Drum, but would BP/UC not have been aware of the potential for reservoir depletion  prior to floating the 8000psi to 9000psi number (emphasis on 9000psi)?

By comparison to the world of financial/economic BS, this seems to me to be a case of retail sales missing analysts estimates because Easter was early this year, or late as the case may be.

"

Transcript-Press Briefing with National Incident Commander Admiral Thad Allen July 13, 2010

The goal is to slowly close that down and understand the changes in pressure as we are closing it until that choke line is closed.  At that point, there’ll be no hydrocarbons exiting from the capping stack.  And we will go into a period where we’re going to start taking pressure readings. It will go in basically 6, 24, and 48 hour increments depending on the results.

And as we said before while maybe counterintuitive to some, in this exercise, high pressure is good.  We have a considerable amount of pressure down on the reservoir forcing the hydrocarbons up to the well bore.  We are looking for somewhere between 8 and 9,000 PSI inside the capping stack, which would indicate to us that the hydrocarbons are being forced up and the well bore is being able to withstand that pressure.  And that is good news.

If we are down around to the 4 to 5 to 6,000 range, that could potentially tell us that the hydrocarbons are being diverted someplace else and we would have to try and assess the implications of that.  And as you might imagine, there are gradations as you go up from 4 or 5,000 PSI up to eight or nine.  The implications of all of that will have a great deal to do with the pressure readings.  What the empirical readings tell us. And then discussions with BP and the science technical team that is here representing the federal government and some of the labs around the country.

We will, at some point, try to get at 8 or 9,000 and sustain that for some period of time.  And these will be done basically, as I said, if we have a very low pressure reading, we will try and need at least six hours of those readings to try and assure that that is the reading.  If it’s a little higher, we’ll want to go for 24 hours and if it’s up at 8 or 9,000, we would like to go 48 hours just to make sure it can sustain those pressures for that amount of time."

http://www.deepwaterhorizonresponse.com/go/doc/2931/779967/

and their statement three days later on July 16 (with the pressure hovering around 6700psi (note the modification in thresholds from the July 13 statement)

Transcript - PressBrief with National Incident Commander Admiral Thad Allen July 16, 2010

We had taken and broken down the hours of the test into six hours, 24 hours and 48 hours, and the thresholds we were looking at is whether or not we achieved certain pressure thresholds.  We knew then within the first six hours if we did not get materially above 5,000 psi that that would indicate high likelihood of damage in the wellbore at some place. 

Moving up, if we were somewhere above 6,000, below 7,500 in the first 24 hours, that would tell us that there was probably some ambiguity regarding the amount of flow or whether or not there was some kind of a leak in the wellhead. 

And finally, if we were to achieve 7,500 or above, that would tell us that there was high integrity and low potential for any loss of flow out of the wellhead.

http://www.deepwaterhorizonresponse.com/go/doc/2931/789331/

Is 7,500psi the new 8,000 to 9,000psi?

I guess Rosie is correct, we do have deflation.

[jeb3]

"7,500psi the new 8,000 to 9,000psi?"

Tell me about it.  Sounded to me like all the news agencies were being reassured that 6756 is the new 8000. 

Damage control as usual.

[divide_by_zero]

Actually Kent Wells said yesterday, contrary to Cooter's remark, that they do have acoustic monitors listening for flow. Also contradicts GW's 8000 minimum number allowing for depletion.

Here's his technical briefing from yesterday afternoon, covers a lot of the above post;

Let me just give you one quick update on our relief wells. Our first relief well is in the process of completing the open hole ranging run. And we’re, when we’re finished that we’ll pull out of the hole and run back in and drill about 30 feet down to our final casing point. Which, at that point, we’ll do another ranging run prior to setting casing. And then I think I’ve described a number of times where we go from there.

Still looking for an intercept point at the end of July. And the kill and cementing process taking a number of days to a few weeks after that.

In terms of the well integrity test. As you heard from Admiral Allen, we’re continuing with it. And, at this point, there is no evidence that the well does not have integrity. That is a good thing.

So let me talk about how is the test going and, quite specifically, what are we monitoring. And I would say the test is proceeding as planned. The pressure continues to slowly rise as predicted by some of the modeling work we’ve done. And I’ll come back and talk to you about that.

So, what are the measurements (doing)? First of all, one of the things we’re doing is we’re measuring the temperature of the casing just right below the BOP. The reason we’re doing that is when the well is flowing, the heat that comes up with the oil and gas from deep down in the, in, below the surface warms up the well bore.

And so, when there’s no flow, the temperature decreases. And so, we were recording the temperature when the well was flowing. And then as we shut it in, we’ve been monitoring. And the temperature has been staying very constant at we’d call ambient temperature. I.e. at the same temperature as the seawater down there.

So, it’s an indication to you that we don’t have any flow at that point. And, of course, one of the lack of integrity issues that we were concerned of is that where the flow, the flow would flow up and then go back down what we call the backside. And go out through the 18-inch casing shoe.

The second thing we’re doing in the same place is acoustic sensing. Where we’ve got an acoustic sensor listening for if we can pick up any sounds that we would associate with flow at that point.

As I’ve indicated before, we have two ROVs that are watching the seafloor immediately around the well. Each scanning 180 degrees. And they’re doing that because we’re watching for any breach in that area. That would be the most sensitive area if we saw any oil and gas coming up from the seafloor or near the well we would want to respond quickly to that. And we’ve got two ROVs specifically watching that. And they have yet to see anything.

We have four ROVs that are using sonar scanning looking in each of the four quadrants around the well. Looking for do we see any anomalies that would indicate we’ve got oil or gas seeping up from the seafloor.

We ran a seismic run, seismic line through it, the, around the well bore before we started the test. And this morning we ran our second one. And we’ve got preliminary analysis of that. And we haven’t seen any indication from the first to the second that would indicate that we’ve got any oil or gas escaping from the well out into the formations.

So, those are the things that we’ve been doing. And all of those, at this point, do not give us any indication that (depluit) we do not have integrity. We will continue to monitor those, paying particular attention to each one of them. And responding if we see anything that would give us a negative indicator.

In addition, over the last couple days we’ve been working with NOAA and others looking at are there some other vessels that we can use to sort of scan the seafloor etcetera. And we’ve got a couple of other vessels that we’re looking to bring in.

I think you heard Admiral Allen talk about we need to be careful at the frequencies they use. They don’t interfere with our dynamic positioning of our, all the other ships that we have out there. But I think we’re working through that. And we’re preparing to do that.

Now let me talk a little bit about the tests and the pressures to hopefully try to bring some clarity. Because I know this is, this is not simple stuff. So, we’ve talked over time that when we ran this test if the pressure did not build up to at least 5,000 to 6,000 pounds, then it would be very clear to us under any scenario that we probably didn’t have integrity of the well. And we’d be looking to open it back up.

We also said that if the pressure got above 8,000 pounds and really the number is 7,500. If the pressure got above 7,500 pounds, it would really say to us that we do have integrity under, essentially, any scenario.

But what we also tried to indicate is that between 6,000 pounds and 7,500 pounds there’s a couple of different scenarios that could take place. And we’d have to monitor very carefully what the pressure buildup is to see what it’s really telling us.

So, you heard Admiral Allen talk about depletion. And when a, when a well flows, like ours has for some period of time, it reduces the reservoir pressure. And that’s what we call about depletion. And when you have depletion it won’t build up to the pressure that you were thinking it might originally before.

You could also have a situation where, if you didn’t have integrity in the well, but you didn’t have depletion, it wouldn’t build up to the pressure that you thought it might to before.

So, those are the two sort of scenarios that we have to monitor. And so, we’ve done modeling under numerous different scenarios. And what I can tell you is that the pressure buildup we’re seeing is consistent with the modeling we did around reservoir depletion and full integrity.

However, it’s very subtle changes. These things are, while we’re doing very precise measurements, the longer we monitor these trends, the more we’ll convince ourselves that that’s actually the case.

And so, it’s exactly why Admiral Allen said we want to continue on with the test. We want to continually monitoring all the things that might indicate that we don’t have integrity in the well to make sure that we do. And so that’s what we’re going to continue to do.

So, we’re going to continue to watch the pressures. The last I looked at the pressures, an hour or two ago, it was around 6,720. We’re seeing it continue to build up in the range of 2 psi per hour. And that’s absolutely following the modeling work we did on a reservoir with depletion associated with it.

So, I think you got a good idea of here’s, we’re monitoring it carefully. We’re going to consult with, between unified command and the government and ourselves every six hours just to make sure we’re all on board.

And then, just want to be very clear, we are poised to move, if we need to, if we were to say to see a breach at the seafloor near the well bore, we would move immediately to open up the well in, what I’ll call a controlled fashion. We need to do it in a way that we don’t damage either the well or the containment equipment that we’ve got.

But we know how we would, we would go about doing that. And, as Admiral Allen said, at least initially, that would involve some venting out the oil to back into the Gulf. But, we’re hopeful that that’s not going to be the case. And we’re going to continue to move forward with our well integrity test and with all the monitoring we’re doing.

[Jim_Rockford]

duplicate (thanks RIM)

[Jim_Rockford]

+1 to gasmiinder, sofa, cooter. Thanks for the education!

[CrazyCooter]

See this post by fdoleza over at TOD (www.TheOilDrum.com) for excellent perspective on one of the many factors at play with regarding the ramp in pressure:

http://www.theoildrum.com/node/6734#comment-678201

Cooter

~~~~~~~~~~~~~~~~~~~~~~

It's complicated. The "oil" is an oil and gas mixture. We use the term gas to refer to the molecules which show up as a gas phase when the well stream gets separated at the surface. In the well, under pressure, the gas is dissolved in the oil. As the fluids move up the hole, they heat the surroundings, and cool down (because there's heat transfer from the fluids to the steel casing and then to the surrounding rock).

There's a very interesting effect many people aren't aware of, when the gas dissolves in the oil, the oil swells. So the oil becomes less dense, less viscous. The swelling factor for this oil could be around say 2. his means one barrel of oil at the surface takes up two barrels at the bottom. And this means the oil down there has a very low density, lower than 50 % that of water.

So let's consider the problem, the oil has been flowing up the well, as it does so it loses pressure, it releases heat to the surroundings, and the gas comes out of solution (the oil "boils"). When it gets all the way to the top and they separate it, they report over 2000 feet of gas per barrel of oil at atmospheric conditions and 60 degrees F, the standard reference.

When they shut the well in, the heating effect provided by the oil flowing up stops, and the column of oil begins to cool down as it loses heat to the surroundings (the gradient would be from say 270 degrees F at the bottom to 40 degrees F at the blow out preventer stack). So, as the oil cools down it begins to absorb a little bit of the gas - but some of this gas migrated to the top of the assembly, which means it won't be in close proximity to the oil and won't re-absorb because the molecules aren't able to move that fast.

Which means the column may end up with volatile slightly undersaturated oil at the bottom, oil that's even more undersaturated in the middle, and then saturated oil towards the top, with gas sitting on top.

And to complicate things, they will also have some oil movement within the reservoir - the lower sand is thicker than the uppper sand, is more likely to be more continuous, and it's more likely to be connected to an aquifer (which provides energy via water expansion as the pressure drops). So it's possible there's flow going on between the two at the wellbore. Even the little stringers of sand higher up the hole may be taking a little bit of oil right now.

This crossflow effect won't allow the reservoir pressure to stabilize, and depending on how much oil each of them produced, and their actual size and properties, it could go on for several months. But I would expect the effect would be very strong at first, and then it would slow down as the thinner oil sand begins to build pressure (because it has oil being injected into it by the lower sand). This effect can be derived from observartion of the pressures they are taking, but last night I did mention they need to model the temperature changes in the well to account for fluctuations in the column density profile. And this can be a bit of a hit and miss affair. On the other hand, they do have the brightest dudes in the industry available to them, so I'm sure they are doing exactly that.

The only thing I proposed and they didn't do, as far as I know, was to place the microphones in the relief wells to listen to the crossflow. I don't have a way to communicate with them, if I did I would get pretty insistent they think about it. And I bet there are people in that organization who proposed just that, but they may not have been heard. OR maybe they modeled the microphone set up and the rock muffles the sound. Or maybe they did run it and they're trying to figure out what the noise they pick up means?

[wang]

Pressure at 6745 +-  they expect it to top out at 6800psi

confidence in well integrity high but lots of seismic, ROV visual and acoustic tests ongoing. Option to extend test period beyond 48 hours. Next briefing Sunday at 7:30 am

[gasmiinder]

GW - when this whole 'pressure test' thing started my VERY first thought was 'how the hell do they have any idea how much the pressure has depleted".  That is a guess on their part.  I don't know the density of the fluids currently in the borehole - but using some reasonable assumptions I'd guess that the we call the "initial flowing pressure" of the blowout was likely around 10,000 psi (I've posted why in other threads).  THAT HAS DEPLETED BY DEFINITION - the question is 'how much'.  The amount of depletion will be a function of 1) the original size of the reservoir and 2) how large an area of water lies beneath the oil - if there is a very large area of water below the oil that will provide more pressure support to the reservoir.  Other things matter but they are more transient in their effects.

After 80 days of almost AOH there MUST be a cell of lowered pressures around the takepoint (borehole).  The size of that area is the question.  The pressure in that cell will equilibrate over time.  Things that will affect the time include the above as well as how permeable the rock is and the geometry of the reservoir (meaning is the replenishment coming from a large circle or is it a channel form so only one general direction is recharging).  In addition to those variables another reason that they are "uncertain" what the test means is because there is NO one on the face of this earth who has experience interpreting pressure results in this particular scenario - so of course they are uncertain.

So - the "8000 psi or the test has failed" is a guess based on multiple estimates and has very wide error bars.  It is VERY likely it is depletion.  I'm still personally of the opinion the entire "what's the pressure - is the well test 'failing'" is essentially diversionary.  THE DAMN WELL IS NOT LEAKING.   There is no loss to the seafloor - that whole meme was always silly but it has taken hold and now we are going through all sorts of contortions to prove it is not happening.

All that said - it is my OPINION if there were a true "underground blowout" (ie an uncontrolled flow of hydrocarbons was fracturing the seal and flowing to the seafloor) the pressure would not be rising 2 psi/hour (or at all).  This is because once the pressure in the hydrocarbons reached above the frac gradient of the 'breach point' they would fracture the rock, flow out and the pressure would stabilize just above that level.  The slowly rising pressure is consistent with depletion or crossflow.  The Columbia professor isn't thinking straight - he'd doing what so many 'experts' have done the last 3 months which is point out something that is true in general about the technology but is silly in application to this situation.

Other minor points to commenters above - the seismic is uncertain but in this situation it will show more than you seem to think.  Depth conversions will be quite accurate.  If a shallower depleted zone has been charged that will show up as will SIGNIFICANT gas injection in to the sediments (insignificant amounts will not).

Bottom line - it looks to me like the bureaucrats HAVE taken over just like so many wanted.  Now people who don't understand the risks are doing what bureaucrats do - making decisions based on absolutes rather than evaluating risks.  Try to keep in mind guys - WE HAVE TURNED THE CORNER.  WE ARE NOW IN THE PART OF THE CURVE WHERE THINGS ARE GETTING BETTER.  And for what seems like the thousandth time - the relief wells are the solution.

[AssFire]

AGREE 100%

GW, pick another topic- sorry no catastropic end.

[CEOoftheSOFA]

+1.  My comments were inserted further up. 

[Fix It Again Timmy]

Dear Assfire,

The world as you know it will end, you can't hide from change, indeed when life is out of balance, expect it!  Show me where the integrity, morality and responsibility are that will allow us to continue the "way we are".  Am I a doomist, nah, I'm having a great time but I don't expect it will last, call me a realist...

[AssFire]

Yes, we are on the cusp of a financial collapse. I only meant to say that your comment has no relation to the well story here. I too am facing the wave of turmoil soon to come and agree our way of life has peaked, I'm no obliviat. Just looking for context.

But as far as the well story goes; it is over- no story anymore except it will be killed shortly.

GW, where is that engineering degree??  Reporting from pitiful sources blindly is no way to go through life son.

[wang]

Media advisory: Kent Wells Technical Briefing

WHEN: July 17, 2010 at 7:30 a.m.CDT

Participant Dial-in US/Canada: [phone],
International callers use: [phone]
Conference ID: 86956141

[CD]

I dunno if it's just me, or are there a lot of strange, strange things going down this sleepy Friday evening:

U.S. Authorities Shut Down WordPress Host With 73,000 Blogs

“We notified him [the Blogetery owner] when we terminated it [the server], and we refunded him his money to his account, because he has other servers with us If he wants the refund to his card, we can easily do that. However, it should be the least of his concerns,” A BurstNet representative later confirmed.

“Simply put: We cannot give him his data nor can we provide any other details. By stating this, most would recognize that something serious is afoot.”

http://torrentfreak.com/u-s-authorities-shut-down-wordpress-host-with-73000-blogs-100716/

State Department warns employees about new website highlighting Top Secret facilities

""The Washington Post plans to publish a website listing all agencies and contractors believed to conduct Top Secret work on behalf of the U.S. Government," the notice reads."

http://www.washingtontimes.com/blog/watercooler/2010/jul/16/put-content-here/

[Jim_Rockford]

It's just you, apparently.

[merehuman]

" do no harm"   hah yea a little late there fella.

All this oil coming out and nothing going in leaves me hanging with a dilemma. Whats replacing the oil and gas or does the ground just cave in to a sinkhole   (28 in china alone and more world wide)

Reality will sink in and folks will realize from the health effects that they need to move  where the rain wont poison them. Florida will be unliveable after one year of this. The coast is unliveable already, its just not acknowledged yet.

[Fix It Again Timmy]

We are f**ked, rationality has been leaving earth at the speed of light since the end of WWII, now there's not much left.  What we are facing is likened to being confronted by a sleep-deprived, epileptic sumo wrestler who just went cold-turkey on a Xanax habit.  This is not going to end prettily...

[Augustus]

I'm interested in what you have used for the measurement instruments.  You may hae marketable tools.

[snowball777]

Great. Now I have to buy Gold *AND* a giant tranq gun?

[AssFire]

And this rant is related to the topic in some way? freaky doomist.

[moneymutt]

so what's with the weird trading in Center Point....is there any merit to this rumor...is Houston in trouble?

[Dapper Dan]

There were 713 put contracts made recently, their 10 day average is 55

Unofficially they have slashed their workforce in the natural gas service side,

[CD]

Just out  of curiosity, is it physically possible for the relief well drills to be closer to the intersect point than BP/CG claim? Just for the sake of argument, could they be hours rather than weeks from reaching the original bore/casing?

[Augustus]

The report is that they are 4.8 ft away fromm the borehole of he blowout well.  At the same time, they are several hundred feet high from where they want the intercept to be.  for all of those who believe that the wild well has saturated the whole GoM seafloor and all formations below the mud line, consider how the relief well is still under control and only protected by 5' of rock.  And farther up the hole of the relief well they drilled through any formations that this 100,000 psi monster is feeding into and did not note any annomoly.  But Matt Simmons knows that the real leak is 7 miles away.

The time to the intercept is based upon the well plan.  That includes the time to set and cement casing very near the bottom of the hole before the final turn for the intercept.  You want to be able to have as much control as possible before the intercept and as much protection of the drill string and loss potential.

[RichardP]

They probably are only hours away with the drill bit.  The thing that will take time - and this has been stated on theoildrum.com and maybe here - is building out the hole that has been drilled and then lowering the equipment needed to bore into the main well.

[CD]

Wouldn't it be ironic if Congress whipped out the old 'material assistance to known terrrrr organization' as the excuse for freezing/seizing assets...

http://www.google.com/hostednews/ap/article/ALeqM5jbVTSczNfhk3s5bc5ph22JI3bbpAD9H0AIL80

[onlooker]

They punched a hole into the unknown and it is still an unknown area. IF we want to explore space and the ocean, there is risk. This situation makes it clear that all the Kings horsemen and all the smart men could not project the drill aftermath. This is progress in the learning process, but how much of the World oceans are gonna die and what is a time frame for recovery---- or is there a recovery. Progressive can overstep control bounds with deadly results. Oil drilling, health bills, banker bills, and

[wang]

here is the unofficial transcript of the 430pm conf call with Adm A

http://unixwiz.net/bp/allen-2010-07-16.txt

[Xibalba]

wait for the earthquake.

[AC_Doctor]

When this was capped Obama was all ra, ra, ra, me, me, me, we, we did this like he dove down and put the adapter and distributer on the BOP with a face mask on only.

If this goes badly, the Kenyan is going to regret this...

AC

[moneymutt]

so, some say Obama blew up this well to get what he wants..how's that working out politically for him....doesn't matter who you are, what party you are...big disasters on your watch always kill your numbers..