Many technical experts have said that the first attempts to complete the relief well in August could miss entirely on the first try, as it is difficult to intersect the blown-out well at the precise location and angle needed.
As PBS notes:
Several experts have compared [intersecting the leaking well with the relief well] to hitting a target the size of a dinner plate two miles underground.
***The ... challenge is to exactly intercept the original well bore, which is only about a foot across. If they miss on the first attempt, they'll need to back up slightly, plug the hole they just made, and try again. Each attempt could take several days. [David Rensink, the incoming president of the American Association of Petroleum Geologists] says that the chances that they'll hit the well bore correctly on the first try are "virtually nil."
"If they're within 20 feet of it, that would be pretty good," he says. However, each attempt will reduce the uncertainty and get them closer, and Rensink says that he's "very certain" that the relief well will work eventually.
"The reason is that they're going to keep at it until they make it work," he says.
If the current relief wells fail, it could be until December or early next year until a correctly-positioned relief well can be completed.
Indeed, ABC News implies that even after the relief well is completed, the Gulf oil may keep on flowing for months. Specifically, ABC points out:
Past experience in the Gulf of Mexico has been sobering. In 1979, a Mexican-owned rig called Ixtoc-1 suffered a blowout and collapsed, and 140 million gallons of oil escaped into the water. Pemex, the Mexican oil company, drilled two relief wells -- and even then oil kept escaping for three months after the first one was finished.Similarly, MSNBC writes:
If the [Ixtoc] disaster serves as a precedent, the BP spill could continue even after the two relief wells are expected to be finished in August.For more on Ixtoc, see this.
In addition, the LMRP cap which BP has installed will not entirely stop the flow of oil. It is only collecting a fraction of the oil gushing from the BOP. As The Oil Drum notes:
The way in which the Shear was used to cut the end of the riser and DP means that it is likely to be impossible at the present time to get a good strong seal around the chamber between the flow into the cap from the BOP and that out into the DP up to the LMRP.Moreover, BP is hesitant to close the "vents" on the LMRP too early, as the buildup of methane hydrates could clog the pipes and stop the LMRP attempt in its tracks - as it did with the attempted "top hat" operation (more on methane hydrates below) . Hopefully, BP can eventually close the vents and increase the amount of oil recovered. See this.
Even if BP can substantially increase the percentage of oil gushing out of the BOP, the cap is not even intended to plug all of leaks. You will see when the underwater cameras occasionally pan around that there are other leaks which aren't even being addressed (indeed, there may be a leak 1,000 feet below the sea floor, and there is a rumor of an even bigger leak 5 to 7 miles away). There is no word yet on whether or not BP will attempt other fixes on other leak areas.
Moreover, as noted by The Oil Drum:
The ship doing the processing [of oil collected from the LMRP cap] is set up to handle 15,000 barrels of oil a day, so that is the upper limit on the amount the system is set up to handle.However, as I pointed out on May 19th - despite BP and the government's attempt to cover up the severity of the spill (Obama was apparently briefed in April how gigantic a problem, and how hard to stop it) - much more than 15,000 barrels a day are being released:
In other words, BP is apparently only planning to recover a small fraction of the oil gushing out of the broken BOP. Obviously, BP could bring in a processing ship with a higher capacity if it can increase the recovery rate. I hope it is possible.Today, a Purdue University mechanical engineering professor - Steven Wereley - testified to the House Committee on Commerce and Energy that 95,000 barrels a day are currently leaking into the Gulf. That's 3,990,000 gallons - just shy of 4 million gallons - per day.The Gulf oil spill is much worse than originally believed.
As the Christian Science Monitor writes:
It's now likely that the actual amount of the oil spill dwarfs the Coast Guard's figure of 5,000 barrels, or 210,000 gallons, a day.
Independent scientists estimate that the renegade wellhead at the bottom of the Gulf could be spewing up to 25,000 barrels a day. If chokeholds on the riser pipe break down further, up to 50,000 barrels a day could be released, according to a National Oceanic and Atmospheric Administration memo obtained by the Mobile, Ala., Press-Register.
CNN quotes the lead government official responding to the spill - the commandant of the Coast Guard, Admiral Thad Allen - as stating:
If we lost a total well head, it could be 100,000 barrels or more a day.Indeed, an environmental document filed by the company running the oil drilling rig - BP - estimates the maximum as 162,000 barrels a day:
In an exploration plan and environmental impact analysis filed with the federal government in February 2009, BP said it had the capability to handle a “worst-case scenario” at the Deepwater Horizon site, which the document described as a leak of 162,000 barrels per day from an uncontrolled blowout — 6.8 million gallons each day.
For background on the Gulf oil disaster, see this.
Note: Some have expressed concern that the release of methane hydrates - the white snowflake-like substance you see in the underwater camera shots - from the oil spill could induce global warming.
However, the cooling effect of the massive amounts of ash being pumped out by the Icelandic volcanoes will likely counteract any warming from the hydrates.
