The planned permanent solution for the BP Macondo spill in the Gulf of Mexico is the killing of the well by drilling a relief well to intersect the blowout wellbore, enabling the placement of high density mud and eventually cement. Currently, two relief wells are being drilled, one started on May 2 and the second on May 14 (although the latter was delayed a few days later on). On The Oil Drum and elsewhere, many have been questioning why only two relief wells have been sunk, given the risky and uncertain nature of the kill process and the long time lag in getting more wells drilled if the first two are unsuccessful. There are many technical, political, and economic arguments that can be used to justify the need for more wells. What I will do herein is develop a statistical model which can be used to weigh the potential benefits of additional wells added this late in the crisis. One of the more critical factors is time -- the time it takes before the blowout wells is killed. Does drilling more relief wells change the expected time before the kill?

This thread is being closed. Please comment on thread http://www.theoildrum.com/node/6578.

Senator Bill Nelson of Florida spoke on MSNBC on Monday, about the possibility of oil leaking up from the seabed in the vicinity of the Deepwater Horizon well that is currently spilling oil into the Gulf. (The implication being that the well casing had "sprung a leak.") The story will inevitably grow, but it may well be that he is confusing two quite separate events. You might remember that when tar balls first started appearing on the Florida beaches recently they were analyzed, and on May 19th the Coast Guard issued a statement that included the following:

A sampling of tar balls discovered on beaches at Fort Zachary Taylor State Park, Fla., Smathers Beach in Key West, Big Pine Key, Fla., and Loggerhead Key in the Dry Tortugas National Park, Fla. were flown by a Coast Guard HU-25 Falcon jet based in Miami, Fla., to New London, Conn. Tuesday for testing and analysis.

The results of those tests conclusively show that the tar balls collected from Florida Keys beaches do not match the type of oil from the Deepwater Horizon oil spill in the Gulf of Mexico. The source of the tar balls remains unknown at this time.

At that time it was conjectured that the tar balls had come from natural seeps under the Gulf. Cutler Cleveland recently wrote a guest post on the topic of these natural seeps, and their size, relative to the current spill, but because of the new furor I thought it worth expanding a little on what he wrote, relying on two of his sources – the National Research Council’s Oil in the Sea III Inputs, Fates and Effects (2003) ; and Dagmar Schmidt Etkin’s Report “Analysis of U.S. Oil Spillage,” which API issued last August.

Matt Simmons has been making claims about other, perhaps larger, problem areas within the structure of the Macondo well--by which even more oil has been pouring into the Gulf of Mexico. We have not seen the evidence to support these claims, even though they have been mentioned in just about every thread we have put up.

Simmons was on with Dylan Ratigan today. That video is shown here in this evening's thread.

VIDEO BELOW FOLD

Please transfer discussion to http://www.theoildrum.com/node/6562.
The decision to cut the riser and drill pipe (DP) from the top of the Blow-Out Preventer (BOP) as a first step in putting the Lower Marine Riser Package (LMRP) over the leaking oil well in the Gulf of Mexico is not quite as easy as it might sound to a layman. This post is going to talk a little about a couple of the problems, as well as an alternate way of doing it, and should end with a possibly slightly amusing anecdote.

The current plan is to carry out the operation in two parts, first the main body of the riser and contained DP will be cut using a large shearing machine, and then a precision cut will be made with a diamond wire cutter to prepare the surface to act as a support and seal for the LMRP. (Illustrations are below the fold). There are a couple of reasons why this is going to be done this way, and one or two concerns that will need to be watched as the operation continues. (UPDATES At 8:45 am I see that the riser in in the shearing machine, at 9:30 am it appears that they are using a diamond circular saw to cut the choke and kill lines - h/t gel. By 11 am they had the wire saw at the riser, and had started to shear the riser beyond the bend. At 12:50 pm after what may be two attempts to shear through the riser and associated piping the shearing machine has been removed from the riser, and appears to have been taken back to the surface ).

(To learn more about the technical basics of LMRP, please go to this post: http://www.theoildrum.com/node/6531)