Could Israel be another Middle East oil giant?
Prospectors in Israel say hundreds of feet below the ground lies shale rock that can be converted into billions of barrels of oil. But environmentalists say it's a disaster waiting to happen.
"This is the distinct smell I'm talking about when I talk about oil shale."
So says Texan oil man, Scott Nguyen, as he sniffs a handful of rock fragments - not back in Houston where he used to work for Shell - but in the lush Valley of Elah in central Israel, about 50km (30 miles) from Jerusalem.
Mr Nguyen wants to prove that oil and gas can be extracted cleanly from Israel's underground shale, using a technology that heats the earth to more than 300C.
The project could be lucrative. The World Energy Council estimates Israel is sitting on enough shale to produce around four billion barrels of oil, enough at today's usage to keep the country in oil for more than 40 years.
Mr Nguyen claims there is much more. That's why he and his colleagues at Israel Energy Initiatives, based in Jerusalem, are lugging rigs around the valley, carrying out prospective drilling.
Shale has been exploited in small quantities in Israel before, but only in a surface-mining operation which generated electricity for local use.
An historic quest
The eager search for home-grown energy in Israel is nothing new.
In recent years, big natural gas deposits were discovered off the coast, but the country still imports much of its gas from its neighbour to the south, Egypt. That supply is precarious. This year it was interrupted by a string of attacks on gas pipelines running through the Sinai desert. And concerns remain about future relations with Cairo, after the fall of Hosni Mubarak - an early victim of the Arab Spring.
In terms of oil, Israel imports nearly all it uses - about 100 million barrels a year - mainly from Russia and the former Soviet republics. Those imports were curbed in 2006, during the war with Hezbollah, prompting the Wall Street Journal to say Israel was "perilously close to running out of fuel".
But despite this hunger for locally produced energy, support for Nguyen and his team is not universal. Some local residents, environmentalists and politicians, are harshly critical.
Back in the US, which has vast shale deposits, drilling was halted in Colorado because the so-called "fracking" method of pumping chemicals into the earth to produce the oil, raised concerns about possible effects on drinking water.
Area licensed to Israel Energy Initiatives for drilling
Similar issues are being debated in Israel, where Rachel Jacobson is active in a local committee opposed to Mr Nguyen's project. "It's really one big experiment," she says, "a foreign company saying we want to make you wealthy. What you are really doing is trying to pull a fast one on us."
Jacobson's concern is, in part, because the drilling area is also the site of a vital and politically sensitive water aquifer shared by both Israel and Palestinian areas of the West Bank.
Mr Nguyen and his team try to calm these fears. In town hall meetings, company representatives tell residents that an impermeable layer separates the shale from the aquifer below. The method of extracting the oil, by heating up the shale, won't have any impact on the aquifer, the company insists.
That doesn't mollify area resident, Meirav Oren. "The company will come in and give really honourable statements like, well, if anything goes wrong we will stop. No-one is asking how will you stop."
Experts seem to disagree on the potential dangers to water supplies of the extraction process. "It sounds scary heating this rock up like this" says John Corben, a senior advisor to the International Energy Agency, "but effects on layers close by are usually not large."
But Mihkel Harm from the World Energy Council says, "the process is hard to control and it might pose a risk for groundwater".
Mr Nguyen's company claims Israel may turn out to have oil deposits comparable to Saudi Arabia, which sits on an estimated 260 billion barrels. Corben says it may not be a fair comparison. He says in Saudi Arabia "oil is actually oil" whereas in Israel a lot of money needs to be spent heating the rock and recovering the oil. And there's a long way to go before the company proves its technology will work, and before it gets all the necessary government permits.
Mr Nguyen's forecast for commercial oil production is 2018 or later. "Still, " says Mr Corben "if it is even 4 or 5 billion barrels, that would be an awful lot of oil for a country the size of Israel".
Additional reporting by Rob Hugh-Jones
You can hear a radio version of this piece at The World, a co-production of the BBC World Service, Public Radio International, and WGBH in Boston. The radio report was first broadcast on The World on 26 September 2011.