BP's (BP) giant discovery of oil is great news for the company, but doesn't alter the overall picture of the world's oil supply.

BP is the most aggressive, and successful, of the major companies when it comes to exploration. This discovery of "more than 3 billion barrels" will encourage the company to continue buying land in the Gulf of Mexico. This will help BP. Todays discovery is worth 1.4%-2.4% of the company's market cap, says JP Morgan in a report.

For the rest of the world though, it's not going to be much help. Analysts believe BP will be pumping out 650,000 barrels of oil equivalent. And that's in 2014, if the company is lucky. At that point, the IEA expects global demand for oil to be around 85 million to 89 million barrels per day, depending on how the economy grows.

Even if there was more oil coming online from the discovery, it wouldn't help the world's economy. The oil will be pulled from deep in the ground. It's as deep in the earth as Mount Everest is tall. For that to be profitable, the price of oil needs to be in the $70-80 range. At that price range the global economy feels a pinch from higher energy costs.

That price range makes the discovery look unremarkable for another reason. It's the same price oil sands producers need to turn a profit. There's 1.7 trillion barrels of oil in Canada. A pessimistic assessment of the oil sands by FBR earlier this year said it could produce 2 million barrels a day by 2015, which is considerably more than BP thinks it will get from this discovery.

That prompted these pithy tweets from energy analyst/writer Gregor Macdonald: "Yes it's very exciting $BP has found oil 7 miles deep (deeper than the Jack Field) that will be more expensive than Oil Sands to develop," and "An irony of Oil Sands is there is virtually no exploration risk. In ultra-deep, you have that ongoing, + cost inflation."

The positive from this? Well, it's tangible evidence that technology for extracting oil is improving. It will encourage more exploration, and with that hopefully comes more oil. It's also providing a nice pop for BP's stock today.

Here's two charts that add some perspective about BP's drilling operations, via Alphaville: