RIYADH: Pakistan is among the top 10 countries with shale oil reserves, a study put out by the Energy Information Agency (EIA), the statistical arm of the US Department of Energy reported last week.

The current global shale resource base is vast enough to cover more than a decade of global oil consumption, the report underlined.

The estimated global reserves of oil in shale rock deposits will boost total world crude resources by 11 per cent, the report said, offering a preliminary glimpse of the hydrocarbons that remain untapped across the world.

In the just released report, World Shale Oil and Shale Gas Resources & Activities, the US Department of Energy estimated a total of 345 billion barrels of “technically recoverable” shale oil resources in 42 countries.

The new U.S. estimate of world shale gas resources stood at 7,299 trillion cubic feet, some 10pc higher than the previous estimate made in 2011. A glaring omission from the assessment though was the highly prospective shale formations beneath large oilfields in the Middle East and the Caspian Sea region.

Shale resources are turning out to be a real game changer. In its five year oil market forecast, last month, the Paris based International Energy Agency too had acknowledged:

“Although uncertainties remain, it is impossible to ignore the possibility that current non-conventional technologies, as they spread and get both perfected and mainstreamed, could lead to a wholesale reassessment of global reserves.”

The EIA assessment points out Russia as the holder of the largest shale oil resource, standing at 75bn barrels. The U.S. with 58bn barrels was next on the list, followed by China (32bn), Argentina (27bn) and Libya (26bn). The list then mentions, Venezuela & Mexico (13bn barrels each), Pakistan and Canada (9bn barrels each) besides Indonesia (8bn barrels). The report also estimates that gas from shale formations increased global natural gas resources by 47pc to 22,882tr cubic feet.

While releasing the report last Monday, Adam Sieminski, the EIA Administrator was frank: “As shale oil and shale gas production has grown in the United States to become 30pc of oil and 40pc of natural gas total production, interest in the oil and natural gas resource potential of shale formations outside the United States has grown.”

But then he cautioned too — spurring a new debate: “Today’s report indicates a significant potential for international shale oil and shale gas, though the extent to which technically recoverable shale resources will prove to be economically recoverable is not yet clear.”

Geology in itself could be an issue. While other countries may have more of these resources than the United States, the impact in some of them may not be as great, or happen as quickly. It could take many years to develop resources in other countries — the techniques that worked in the United States might not quite work elsewhere.

What’s more, many countries don’t have the needed technological expertise too. And then water could be a limiting factor too at some places.

Technically recoverable reserves are thus not a guarantee of supply and it is unclear if deposits outside the United States, with varying geology, can be developed economically or not. Even inside the United States some areas have proved to be more difficult and expensive to develop than others, halting development.

Poland, ranked twelfth in the list of shale gas reserves, attracted a lot of interest in its shale potential. Yet faced with difficulties, oil majors have since quit shale drilling there.

The report too admits: “Shale oil and shale gas resource estimates are highly uncertain and will remain so until the shale basins are extensively tested with production wells.”

Uncertainty remains the king — in this game of hide and seek!