Friday, July 16, 2010
If you don't know what the results of BP's oil well integrity test are, you're not alone.
As I pointed out Wednesday:
BP suspended the "top kill" operation for 16 hours - because, according to numerous experts, it was creating more damage to the well bore - without even telling the media, local officials or the public that it had delayed the effort until long afterwards.
BP also admitted - many days after it stopped the top kill attempt - (1) that BP had to stop because mud was leaking out below the seafloor, and (2) that capping the well from the top could blow out the whole well.
Similarly, it took more than 5 hours for BP to publicly announce the delay of the "well integrity test" after the decision to delay was made.
So BP doesn't have a great track record of promptly informing us of what is happening.
Because so little information is being released, even oil industry experts like Rob Cavnar are resorting to watching the underwater video cams to try to figure out what's happening.
And Cavnar says that BP and the government are making things up on the fly, so it is a very fluid situation, and that long periods of silence mean that something is happening:
It’s clearly been on the fly. There’s a lot more discussion behind the scenes obviously with the government and bp team than what they’re disclosing to the public. What I’ve learned in this whole experience, if you get a long on period of silence, something’s going on. I think that’s a lot of what happened today.Fortunately, Cavnar says that it looks like BP is doing a thorough job of monitoring visual and sonar images for leaks.
For example, the Geco Topaz is conducting seismic surveys over a range of many miles. Indeed, the Topaz has sailed perhaps 50 miles in and around the site of the oil gusher. See this and this (the Topaz is the ship indicated in light blue).
So What Do We Know?
Even independent oil industry experts are guessing at this point because BP is keeping everything close to the vest (and that some allege that the government is not publicly disclosing what it knows).
And the stakes are high. As president Obama said this morning, there is a risk that - if the well is incorrectly capped - numerous leaks could spring from the seafloor:
(starting at around 30 seconds.)
So the question is what we do know at this point?
Putting aside Matt Simmons' (Simmons was an energy adviser to President George W. Bush and was a prominent investment banker to the oil industry) claims that there is a conspiracy to cover up a larger leak miles from the cap - for which there's been no independent confirmation to date - here's everything that we know at this point:
- Well pressure is currently a little above 6,700 psi, far short of the 8,000 psi which would prove that the well integrity is more or less intact.
- If the well pressure keeps rising, and stabilizes at 8,000 psi or higher, then the well is fairly stable, and the below-seafloor damage to the well is not significantly impacting well strength. It would not be unexpected for the pressure to start lower and then to rise, so at least another 24 hours is needed to get the final result. BP says "The pressure has been a very steady build as predicted by engineering anlysis we did. " BP also says that the seismic, sonar and visual inspections so far indicate "no negative evidence".
- If well pressures rise and then suddenly drop, then the well integrity test itself has caused a new leak.
- If well pressure stabilizes far below 8,000, then there are major leaks. 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).