Oil revenue is a huge portion of the Venezuelan economy Chavez needs to stay in power. It may jack up the price of oil in the short term but he has to sell his oil to someone, so does Iran... they cannot afford to not sell their oil.
So if overall supply remains the same, then at most it will simply increase the cost of shipping the oil. Would also likely increase the price a bit as people don't like instability like that would promote.
Are you sure the US is the only client in the world looking to buy Venezuelan oil?
This is from 2006 ...
Venezuela Cautions U.S. It May Curtail Oil Exports
By JUAN FORERO
Published: February 27, 2006
http://www.nytimes.com/2006/02/27/international/americas/27venez.html
BOGOTÁ, Colombia, Feb. 26 — Venezuela's oil minister, in blunt comments published in a Caracas newspaper on Sunday, warned the United States that it could steer oil exports away from the United States and toward other markets.
The minister, Rafael Ramírez, said Venezuela, which is the world's fifth-largest oil exporter and supplies more than 10 percent of American oil imports, could act in the face of what he described as aggression by the Bush administration.
Although such warnings have become part of President Hugo Chávez's verbal arsenal against the Bush administration, the comments by Mr. Ramírez, coupled with the increasing sale of oil to China, are seen by oil experts and political analysts as a signal that Venezuela is serious about finding new buyers.
"Physically it's very feasible, and politically it's very feasible," said Lawrence Goldstein, president of the Petroleum Industry Research Foundation, a New York policy analysis group financed by the industry. "It comes with an economic penalty, but apparently Chávez is willing to pay that price."
That economic penalty comes in the increased costs to transport crude from oil-rich Latin America to as far away as China and India, two fast-growing, energy-hungry giants that are eager to buy Venezuelan oil. China is a 30-day tanker trip from Venezuela, while the United States is just 5 days away and is well-equipped to refine the heavy, highly sulfurous Venezuelan oil .
Mr. Chávez's government, which has increasingly been sparring with the Bush administration over everything from the Iraq war to the Venezuelan leader's close ties to Cuba, is moving swiftly to forge energy ties with China. Venezuela has said that this year it will double exports to China, to 300,000 barrels a day. Venezuela ships about 1.5 million barrels a day to the United States.
--more at link