This year's Christmas won't be so merry under a worst-case scenario released Wednesday by a major energy investor.

Writing about BP's effort to plug a leak from a drill site that became exposed after a deepwater oil rig burst into flames and sunk in April, an energy investor noted that the company's success rate didn't promise well for its would-be ultimate solution. BP plans to drill two "relief wells," near the drill site, that in theory would allow the company to finally staunch the massive flow of oil spurting from the earth 5,000 feet under the Gulf of Mexico.

“The worst-case scenario is Christmas time,” Dan Pickering, research director for energy investor Tudor Pickering Holt & Co., told Bloomberg News for a story Wednesday. “This process is teaching us to be skeptical of deadlines.”

Ending the year with a still-gushing well would mean about 4 million barrels of oil spilled into the Gulf, based on the government’s current estimate of 12,000 to 19,000 barrels leaking a day. That would wipe out marine life deep at sea near the leak and elsewhere in the Gulf, and along hundreds of miles of coastline, said Harry Roberts, a professor of Coastal Studies at Louisiana State University.

So much crude pouring into the ocean may alter the chemistry of the sea, with unforeseeable results, said Mak Saito, an Associate Scientist at Woods Hole Oceanographic Institution in Massachusetts...

The so-called relief well being drilled to intercept and plug the damaged well by mid-August might miss -- as other emergency wells have done before -- requiring more time to make a second, third or fourth try, Dave Rensink, President Elect of the American Association of Petroleum Geologists, said.

A spokesman for BP declined to comment.

Late Tuesday, a remote controlled submarine successfully cut into the Deepwater Horizon's riser pipe, creating a fresh oil gusher that BP hopes to fit with a cap once a diamond saw can be used to ensure the cut is perfectly clean.

The dramatic scene played out on live streamed video, watched by thousands all over the world.

"When the robot submarines cut into the undersea well's riser pipe, a fresh spew of oil temporarily obscured the view of the mechanical arm," CNN reported. "The cut was a first step toward placing a cap over the well that has spewed hundreds of thousands of gallons of oil into the Gulf of Mexico every day since late April."

BP chief operating officer Doug Suttles told the network the fresh attempt to plug the oil gusher could succeed as early as Thursday. The company plans to fit a long tube onto the cap and funnel the gushing oil into a tanker ship.

The risk of the maneuver, CNN added, is that it could increase the flow of oil by 20 percent.