BP's Deepwater Oil Spill - Storm Threat, Current Production, and Other News - and Open Thread
This thread is closed. The new thread is http://www.theoildrum.com/node/6663.
The storm moving through the Gulf of Mexico is becoming more of a concern. It was upgraded to a tropical depression late Friday afternoon, and there is a possibility of a second storm forming out further east. Chuck Watson is providing updates on the storm on his post.
Admiral Allen has indicated that evacuation decisions are based on predictions of when gale force winds, of about 40 knots, might hit. The federal on-scene co-ordinator makes a decision about five days, or 120 hours before gale force winds are expected to hit. The five day cone of the storm center gives a rough idea as to where this might be. Chuck Watson will be providing a map later today giving a 40 knot "cone" forecast, which is really the area of concern. I have put a red square roughly where the Deepwater Horizon site is, as a point of reference.
The actual time it is expected to take to disconnect different kinds of equipment varies. According to Admiral Allen, the time needed to "secure and evade, including 24 hours for transit" is 114 hours for the Discoverer Enterprise and 54 hours for the Q4000. With both of the ships removed, the oil and gas being emitted (estimated at 35,000 to 60,000 barrels a day) would flow directly into the Gulf of Mexico, without any containment.
Work on relief wells would need to be discontinued, pushing back the date of completion. Since taking down, evacuating, return transit, and setting back up takes several days minimum, and forecasting isn't very good several days in advance, there may be several interruptions this summer for storms, or possibilities of storms, some of which are false alarms. Each evacuation will delay the relief well effort, and lead to more oil being spilled, which is not captured by ships.
Other Briefing News
Also in the briefing, the Admiral explained the location of the initial well and the relief well (RW) (one relative to the other) in a little more detail. Now that the initial location of the well has been established, the RW is drilling back downwards. But every so often it will stop and:
This is where they withdraw the drill pipe and put down an electrical cable into the end of the wellbore, and they put out an electrical signal, and they actually could pick up the magnetic field around the wellbore. This tells them how close they are getting.
They have made contact with this electromagnetic field. What they will do is continue to drill down in short intervals, withdraw the pipe, put that sensing device down, and slowly close on the wellbore to the point where they're ready to do the intercept drilling.
This last part takes some time, because they only do several hundred feet at a time, withdraw the drill pipe, and then put the sensor down to figure out how close they're coming. After a series of these readings, they can have a very precise idea of how close they are to the wellbore and then how to actually turn the drill in and make the intercept. But then we'll get much slower, because they have to basically drill, withdraw the drill pipe and put the sensor down.
They also have a vessel standing by that's full of mud on the top, in the event they get really close, they could potentially knick the wellbore they could actually put mud down to control any hydrocarbons that might come out.
Regarding the longer-term containment, we should by next week have the additional vessel in place to start producing off of the kill line. That's the other line that's available to bring oil to the surface. That will bring us the three production vessels and the 53,000-barrel capacity we were looking for by the end of June.
In the change to a new cap that is planned for next week, there are three different designs that are being considered for installation. The ROVs are currently hooking up the hoses to the new distribution system that will ultimately feed four risers.
The recovery operation has returned to collecting about 24 kbd:
• For the first 12 hours on June 25 (midnight to noon), approximately 7,870 barrels of oil were collected and approximately 4,230 barrels of oil and 27.5 million cubic feet of natural gas were flared.
• On June 24, total oil recovered was approx. 23,725 barrels:
• approx. 15,785 barrels of oil were collected,
• approx. 7,940 barrels of oil were flared,
• and approx. 54.7 million cubic feet of natural gas were flared.
Effect of Cap Replacement
A couple of days ago, the cap was off, and put back on. When the view from the cameras is examined, the pictures are a little different from earlier. The camera on the Enterprise ROV2, for example at 9:50 pm on June 24 is showing no oil leaking from under the cap.
In contrast there is still some volume leaking on the Skandi ROV2 side of the cap – but the body of the cap can be clearly seen, suggesting that the draw-off of the oil and gas is reaching the totality of the flow.
View of the cap and leak from the opposite side (Skandi ROV2) where the body of the cap can be clearly be seen, suggesting that almost all of the flow is now being captured, since the oil and gas leaking out are much reduced in flow.
However both these views do not show what is happening at the top of the cap, where the vents are that allow oil and gas to escape from the top of the cap. But this suggests that the well flow is coming more under control, and that as the four new riser pipes are put into place, and more flow is extracted through the choke and kill lines, that the leak into the Gulf can be reduced to almost zero, which will then happen as the new cap is put into place next week (assuming no hurricane interruption).