HOUSTON -- The Gulf of Mexico's deepwater environment will be the most active offshore drilling zone in the world over the next two decades, with investments there surpassing those of all other regions combined, an energy and metals research firm declared yesterday.

Through 2030, the deepwater Gulf is predicted to attract more than $70 billion in investments in new production, analysts at Wood Mackenzie forecast yesterday in a briefing with reporters.

The offshore oil and gas research team there also foresees drilling activity in waters off the coast from Texas to Alabama finding its footing and taking off in 2013, with the industry reaching a new production peak six years later.

The $70 billion investment forecast assumes a conservative international Brent crude oil price at or above $85 per barrel.

"We expect around 12.5 billion barrels of oil equivalent will be found from that investment," said Wood Mackenzie offshore analyst Julie Wilson. "Only Brazil materially surpasses the volume and value" that companies are finding in the Gulf of Mexico, she added.

The results are slightly counterintuitive, the researchers acknowledged. Though heavily explored and thoroughly mapped with the newest seismic surveying technology, the Gulf of Mexico often carries a higher risk than other regions, while the eventual finds can be smaller, the team said. Exploration costs can also be higher compared with other offshore oil and gas zones.

But the benefits to investing in the Gulf seem to be more than outweighing the risks involved. Wood Mackenzie cited a favorable regulatory climate that companies are increasingly good at dealing with, existing acreage holdings that firms acquired long ago, and an abundance of available infrastructure.

Analyst Norm Pokutylowicz said that on average 75 percent of the offshore capacity in the Gulf of Mexico is unused, representing an enormous overcapacity of infrastructure available to tap into.

He cautioned that this estimate did not include peak time usage or capacity deliberately set aside by companies, but nevertheless the abundant pipeline and platform infrastructure available for new projects to tie back into provides further incentives to invest there.

"The message is the same -- a lot of the capacity is unused," Pokutylowicz said.

Infrastructure in the Gulf is so well developed that Wood Mackenzie analysts predict the Gulf will not become a major home to one emerging new trend in offshore oil and gas: floating production, storage and offloading (FPSO).

Though Brazilian energy giant Petrobras has introduced one FPSO system into the Gulf, analysts at Wood Mackenzie see few others following in that company's footsteps. The Jones Act, which requires that any shuttle tankers that would be used in an FPSO operation be built in the United States, puts a further roadblock in the way of that technology becoming a significant presence in offshore waters here, they added.

The new regulations that have emerged in the wake of the 2010 Gulf of Mexico oil spill are still making an impact on the speed with which new wells can be drilled there.

"Overall, wells are taking about 10 percent longer to drill post-Macondo," said deepwater analyst Lauren Payne.

Still, Payne said she didn't expect this to continue as companies become more familiar with the new requirements they face. The delays are attributed to the time it takes for conducting more in-depth testing of blowout preventers, and delays have been largely felt at projects piercing the deeper Miocene plays. Elsewhere the impact has been flat, and Payne said she didn't expect the 10 percent increased drill time figure would last.

Wood Mackenzie believes Gulf of Mexico production will hit a new peak in 2019, at 2 million barrels of oil equivalent per day. Production is expected to increase after that, but that view is contingent on global oil price dynamics and on how prolific new projects coming online turn out to be.

Giant prospects to look for, analysts said, include areas in the subsalt Miocene trend and Paleocene, both ultra-deepwater zones estimated to hold around 4.3 billion and 5.2 billion barrels of oil equivalent, respectively.

And there should be plenty of rigs available for the industry to continue increasing its Gulf output, Payne said, at least in the near term.

"We actually don't get into a constrained rig environment until 2015," she said.