* BP well flow estimated at 35,000-60,000 barrels per day
* U.S. govt has revised flow estimate upward three times
* U.S. says latest number is most comprehensive to date
(New throughout, adds details, background)
By Kristen Hays
HOUSTON, June 15 (Reuters) - A team of U.S. scientists on Tuesday upped their high-end estimate of the amount of crude oil flowing from BP Plc's (BP.L) (BP.N) stricken Gulf of Mexico well by 50 percent, the second major upward revision in less than a week.
The scientists said the "most likely flow rate of oil today" ranges from 35,000 to 60,000 barrels (1.47 million and 2.52 million gallons/5.57 million and 9.54 million litres) per day.
That is a significant jump from the last estimate issued by the Flow Rate Technical Group on June 10 and pegging the well's flow at 20,000 to 40,000 barrels per day.
And those figures were considerably higher than the previous "best estimate" of 12,000-19,000 bpd issued by the flow rate group on May 27.
"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," said Energy Secretary Steven Chu.
The team of scientists said they may revise the estimates again as they gather new data on the well, one mile (1.6 km) beneath the ocean surface.
Even at the minimum estimated rate of 35,000 bpd, the ruptured well has dumped nearly 2 million barrels of oil into the Gulf of Mexico since the Deepwater Horizon rig exploded on April 20 -- nearly eight times the amount that the Exxon Valdez spilled into Prince William Sound in Alaska in 1989.
At the U.S. government's direction, BP is boosting its oil capturing capacity to up to 53,000 bpd by the end of June and to 80,000 bpd by mid-July from about 18,000 bpd.
The new estimates come from detailed pressure data taken by instruments inside BP's oil-containment device on the sea floor over the last 24 hours, the government said.
"This estimate, which we will continue to refine as the scientific teams get new data and conduct new analyses, 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 in a statement. (Additional reporting by Chris Baltimore; editing by Chris Wilson)