John Schiller, founder of up-and-coming energy company Energy XXI, has made a $1 billion acquisition of most of ExxonMobil's oil fields in the Gulf of Mexico.

The move gives his company majority control of nine fields and 130,000 net acres with 50 million barrels of proven reserves — and effectively doubles the company's size. It also positions the small Houston-based company as the third largest oil producer in the Gulf, behind energy giants Apache and Chevron.

The company is already feeling the effects; after news of the acquisition broke on Sunday, Exxi's stock rose approximately 8.5 percent.

Schiller sums up the deal for CultureMap: "It's a big transaction; it makes a lot happen."

Schiller added that the move increased reserves 65 percent, increased cash flow 75 percent and resulted in a 15 percent increase in the company's staff. "It puts us at the $3 billion enterprise level," he said.

Exxi is known for it's ultra-deep drilling, often at depths of more than 30,000 feet, but Schiller told Forbes in a recent profile that he plans instead to drill sidetrack wells into existing reservoirs in mature fields like the ones acquired from ExxonMobil. Although Schiller downplayed the use of ultra-deep drilling technology immediately, he said he estimates that Exxi's current projects have the potential to access 100 trillion cubic feet of natural gas — enough to power the entire United States for four years.

"There's no quick timetable required to get to the drilling opportunities, so we'll identify them and stack them against everything else we have to drill, and we'll drill the best prospects first," Schiller told CultureMap.

Other major projects Exxi is working on include discoveries at Davy Jones, Lafitte and Blackbeard East. Schiller says he expects Exxi's $250 million budget this year to creep to $300 million with the deal's completion. (Exxi's fiscal year ends in July 2011).

The deal is expected to close Dec. 20. Although Schiller says we shouldn't expect any more major acquisitions from Exxi for a while, the next piece of huge news from Exxi might just be a rumored eventual merger with drilling partner McMoRan, with Schiller succeeding Jim Bob Moffett as its head.

The A&M graduate, who is married to Houston social figure Kristi Schiller, has 30 years experience in the oil and gas industry and worked for a number of successful energy companies including Devon Energy, Ocean Energy, Seagull Energy, Meridian Oil and Superior Oil before founding his own company in 2005.