Gulf oil spill: Flow rate now 35,000 to 60,000 barrels per day, panel says [Updated]

As many as 60,000 barrels of oil per day may be flowing from the blown-out wellhead in the Gulf of Mexico, according to the newest government estimates.

Basing their calculations partly on pressure readings from the wellhead and acoustic soundings, a team of federal and independent scientists said Tuesday the current daily well flow ranges from 35,000 to 60,000 barrels per day. The figures are the latest in a series of flow estimates that have steadily risen in recent weeks, but they may not be the last.

"As we continue to collect additional data and refine these estimates, it is important to realize that the numbers can change," said Energy Secretary Steven Chu. "In particular, the upper number is less certain, which is exactly why we have been planning for the worst-case scenario at every stage and why we are continuing to focus on responding to the upper end of the estimate, plus additional contingencies."

[Updated at 4:04 p.m.: Federal officials said they have greater confidence in the latest numbers than earlier ones because the new calculations are based on a greater variety of data. “This estimate brings together several scientific methodologies and the latest information from the sea floor, and represents a significant step forward in our effort to put a number on the oil that is escaping from BP’s well,” Chu said.

The new flow rates are based on high-resolution videos taken by underwater robots, acoustic soundings, new pressure readings from inside the recently installed containment cap and measurements of the volume of oil the cap is funneling to a production ship.

“This estimate ... is the most comprehensive estimate so far of how much oil is flowing one mile below the ocean’s surface,” Interior Secretary Ken Salazar said.

The higher flow rates are ratcheting up pressure on BP to quickly get enough tankers and equipment on site to capture the full amount.

On Monday, 15,420 barrels of oil were collected. The system BP currently has in place can capture up to 18,000 barrels a day. The company is adding additional capacity that will soon give it the ability to handle up to 28,000 barrels.

That will grow to about 50,000 barrels per day by the end of June and 60,000 to 80,000 barrels by mid-July, federal officials said.

The new estimates take into account any increase that occurred when a riser pipe attached to the well was sliced off early this month. Engineers had previously said the cut might push up the flow by as much as 20%. But Tuesday's release did not discuss the cut's effect. ]

In the early days of the spill, oil company BP and federal officials said the flow was 1,000 barrels per day, a figure that was ramped up to 5,000 after an environmental group challenged the figures. The scientific panel was formed, and it issued a preliminary estimate of 12,000 to 19,000 barrels per day. Last week, the same group upped its estimate to 20,000 to 40,000 barrels per day.

The day after the April 20 explosion of the Deepwater Horizon rig, the U.S. Coast Guard evaluated the "potential environmental threat" of a spill and concluded that, in addition to 700,000 gallons of diesel from the vessel, there was an "estimated potential of 8,000 barrels per day of crude oil, if the well were to completely blow out," according to Coast Guard documents released last week.

Two days later, Coast Guard logs included a new estimate that a full blowout could result in a spill of 64,000 to 110,000 barrels per day. (A barrel equals 42 gallons.)

-- Bettina Boxall

Comments

[dan ritchie]

I believe the flow rate is at least 50 gallons/second, 3000 gal/min,180,000 gal./hr or 4,320,000 gal/ day. the hydraulic head is just enormous......... and even 50 gal/sec is probably conservative with that type of velocity and pressure head.

[John Weddig]

Using BP's capture numbers and assuming 100% capture I get these numbers.
88,000 bbl methane/oil mixture released per day.
29.26% of the mixture is oil leaving 25,800 bbl of oil per released.
The methane/oil mixture is being released under 5000 ft of water. At 1 atmosphere per 33 feet the water pressure is 151 atmospheres. Other methods give a value of 147.5 atmospheres. Therefore the 26,000,000 cubic feet of gas BP collected and burned June 18 is compressed to 176,000 cubic feet at the oil head. Converting BP's captured and burned values to cubic feet you get a captured flow rate of oil/methane of 5.805 cubic feet per second.
For the past sixty days excluding methane:
1,552,000 bbl released
217,000 bbl captured
1,335,000 bbl lost into the Gulf

[Andrew N. Guthrie former NBC News and Voice of America correspondent]

To the LA Times Science Desk: The most threatened species of all major animals by the Gulf spill is the Kemp's ridley sea turtle. Your Texas Bureau did a wonderful story I still have in my file about five years ago on the US- Mexican effort to head off extinction for this turtle. Within days mother turtles will finish nesting on Texas coast and head for the now-toxic blue crabs, their favorite food, off the Mississippi Delta. and Eastward. I have a plan to save some of them but can not get anybody to listen to me. I've checked with Donna Shaver, PhD leader of the national Park Service recovery effort on Padre Island National Seashore. She agrees with me! See front pg. NYTimes 19 May for my previous effort at getting out the word. Call me for more at (703) 471-6769 or Cell (703) 447-2644. It gets the LA Times AHEAD of the next big thing in the spill which will be MAJOR Kemp's ridley die off!!!. Regards, Andrew Guthrie Reston, VA