U.S. resource plays that are spewing out natural gas and oil have virtually cleared producer calendars of speculative drilling and made for an energy supply bounty that is becoming the envy of numerous companies around the world, speakers at a Houston energy conference said.

"The visibility of what you now have, of what you will be doing for decades is a stunning development," said Maynard Holt, co-president of Tudor, Pickering, Holt & Co. Inc. "What it has allowed...is...financial investors who weren't used to taking geologic risk or subsurface risk, now they will take it. It has allowed public investors who were only willing to pay so much per flowing barrel...it has allowed them to pay much more."

In other words, buckets of money have become available for North American oil and gas development, he said.

Only about a decade ago it was a "different world" for Lower 48 natural gas. "It looked like a dream investment: 'I'm going to invest in something that I know demand is growing for and I know that supply is getting harder and harder to get'...very similar to what's happening with oil today when you think about how people feel about oil.

"There was so much confidence around gas that it began to let loose a lot of horses. ...[A]t that time...we were talking about the Barnett Shale as if it had landed from space: 'There's this thing called the Barnett Shale, and wow, and 60 Minutes did a story,' and so forth. But the thinking wasn't, 'Wow, if it works here why wouldn't it work in five or six other places, etc.' It was still just a new phenomenon."

Oil and gas is now more of a technology play than ever, Holt said. The repeatability of success in the shale plays has removed the exploration risk from the game to deliver a backlog of gas and oil reserves the dimensions of which are yet to be fully understood. Companies in other parts of the world have noticed what's going on in North America, too, Holt said.

"When we travel abroad, the fascinating thing is those companies look at you and say, 'You have something that I desperately want. You have cheap energy. You have cheap, clean energy...and I can't see my way to having that.'"

Indeed, Holt said overseas investors in U.S. shale plays do stand to receive a technology transfer payoff, but it's not as significant as is often touted, and it's not the main driver for most overseas investors. "It's [the United States] just a good place to put money; it's just a good investment."

Overseas, shale plays are not likely to soon rise to the levels seen in North America, Holt said. "International shale, the more you look at it, the harder it appears. Although there's all this technology transfer and this that and the other, it really looks hard."

Back home, the industry has the opportunity to generate an energy supply that was not thought possible just a few years ago, said Chevron's Robert Ryan, vice president of global exploration. "It's not a renewable agenda; it's not a nuclear agenda; it's not oil, gas, coal. It's an energy agenda."

However, oil and natural gas are likely to feel the weight of the country's energy needs falling more heavily on their shoulders, he said. "Some of those pieces are under pressure and maybe they will not be able to deliver their piece of the curve, and that steps up the pressure on what we [in the oil and gas industry] need to do."

The nuclear power industry, on the cusp of a renaissance, has seen much of its hopes dashed following the Japanese nuclear disaster, he said. Natural gas is among the energy sources that has been called upon to take up the slack for shuttered nuclear units, he noted.

Coal-fired power, long a mainstay, is facing new headwinds in the form of stricter environmental controls that are predicted to drive many plant owners to shut down aging units rather than pay for expensive retrofits, he added.

Renewable power will be part of the mix, particularly that from solar and wind, but renewables lack the scalability and scope to contribute nearly as much as oil and gas, Ryan said.