CALGARY - Staggering amounts of oil and natural gas are locked in once-ignored Alberta rocks, according to a study released this week by the Energy Resources Conservation Board and Alberta Geological Survey.

The report estimates those tough-to-access areas contain 423.6 billion barrels of oil, 3,424 trillion cubic feet of natural gas and 58.6 billion barrels of natural-gas liquids.

However, it's not known how much of that resource can be tapped using today's technology and in the current economic environment.

Five formations in particular — The Duvernay, Muskwa, Montney, Nordegg, and Basal Banff/Exshaw, also known as the Alberta Bakken — show immediate potential, the report said.

The study also included preliminary assessments of the Colorado, Wilrich, Rierdon and Bantry shales.

The researchers looked at 3,385 samples for the report.

"Data and information on reservoir characteristics and hydrocarbon resource potential of shale formations are rare because of the historical lack of interest in shale-hosted hydrocarbon reservoirs," the report said.

"Now, industry is looking for data and information on shale gas resources to decide if and where these resources may be developed."

The Duvernay, an emerging region where companies such as Encana Corp. (TSX:ECA) and Talisman Energy Inc. (TSX:TLM) are active, is estimated to contain 443 trillion cubic feet of gas, 11.3 billion barrels of natural gas liquids and 61.7 billion barrels of oil.

Celtic Exploration Ltd. (TSX:CLT), which also has acreage in the Duvernay, recently agreed to be acquired by Texas energy giant ExxonMobil Corp. (NYSE:XOM) for $3.1 billion.

Those companies are also active in the Montney, which is estimated to contain 2,133 trillion cubic feet of gas, 28.9 billion barrels of natural gas liquids and 136.3 billion barrels of oil.

Development of shale formations such as the Montney and Duvernay have heated up in recent years as industry players continue to hone their extraction techniques. Those include drilling long wells that stretch horizontally through a formation and fracturing the rock to free the oil and gas.

Also on HuffPost:

Loading Slideshow...
  • PRO: Potential Energy Independence

    Estimates by the <a href="" target="_hplink">United States Department of Energy</a> put the number of recoverable barrels of shale gas at around 1.8 trillion. To put that into perspective, Saudi Arabia is estimated to have roughly <a href="" target="_hplink">2.6 trillion barrels of oil reserves</a>. Christopher Booker writes for <em>The Telegraph</em><a href="" target="_hplink"></a> that there are enough world reserves to "keep industrialised civilisation going for hundreds of years"

  • CON: Water Pollution

    A <a href="" target="_hplink">blog post by the Natural Resource Defense Council</a> explains that "Opponents of such regulation [of fracking] claim that hydraulic fracturing has never caused any drinking water contamination. They say this because incidents of drinking water contamination where hydraulic fracutring is considered as a suspected cause have not been sufficiently investigated." It then goes on to list more than two dozen instances of water pollution to which hydraulic fracking is believed to have contributed. A <a href="" target="_hplink">new waterless method of fracking</a> has been proposed, but environmentalists are skeptical.

  • CON: Leaks More Emissions Than Coal

    Methane is a greenhouse gas and <a href="" target="_hplink">major component of shale's carbon footprint</a>. Cornell Professor Robert Howarth said about a study he conducted, "Compared to coal, the footprint of shale gas is at least 20 percent greater and perhaps more than twice as great on the 20-year horizon and is comparable when compared over 100 years."

  • PRO: Burns Cleaner Than Other Fossil Fuels

    <a href="" target="_hplink">Researchers at MIT found that</a> replacing coal power plants with natural gas plants could work as part of a plan to reduce greenhouse emissions by more than 50 percent.

  • CON: Hydraulic Fracking Has Been Linked To Earthquakes

    <a href="" target="_hplink">Several earthquakes both in the U.S. and abroad </a> have been linked to the hydraulic fracturing process. One British company, <a href="" target="_hplink">Cuadrilla Resources</a>, admitted in a report that its hydraulic fracturing process well "did trigger a number of minor seismic events."

  • PRO: Jobs

    <a href="" target="_hplink">The industry currently employs more than 1.2 million people</a> in the U.S., and the Department of Energy estimates that natural gas resources have increased nearly 65 percent due to fracking, according to a TreeHugger graphic. Additionally, <a href="" target="_hplink">the gas industry accounts for about $385 billion</a> in direct economic activity in the country, a <em>Nature</em> piece reports.

  • CON: Companies Don't Have To Disclose Chemicals Used In Process

    <a href="" target="_hplink">Fracking is exempt from the Safe Drinking Water Act of 2005</a>, thus allowing companies to conceal the chemicals used in the process.

  • PRO: Buys Time To Develop Renewable Energy

    Former chief of staff to President Clinton and former head of the Center for American Progress <a href="" target="_hplink">John Podesta says natural gas can serve</a> "as a bridge fuel to a 21st century energy economy that relies on efficiency, renewable sources, and low-carbon fossil fuels."

  • CON: Requires Large Amounts Of Water

    The fracking process can require around <a href="" target="_hplink">five million gallons</a> of water. In some cases<a href="" target="_hplink"> less than a third of that water is recovered</a>.