Bahrain announced on Wednesday that the shale oil reserve newly discovered off its west coast contains more than 80 billion barrels.
The amount of recoverable oil -- or oil that can be extracted -- is still under study, Oil Minister Sheikh Mohammed bin Khalifa Al-Khalifa told a press conference in Manama.
The field covers 2,000 square kilometers (772 square miles) in shallow waters off the kingdom's west coast.
The new field would in theory dwarf the Bahrain Field, the country's only other oil field, which contains several hundred million barrels.
The actual impact of the discovery is contingent on how much of it is actually extractable.
Yahya al-Ansari, exploration manager at Bahrain's national oil company Bapco, said that the pumping of oil from the field is not expected for at least five years.
Speaking to reporters after Wednesday's press conference, Ansari said Bahraini authorities, in cooperation with international oil companies, were trying to establish how much oil can be extracted.
"What we have announced is oil in place ... So far, we don't know how much of it can be extracted and the cost of its production," two important elements that could determine whether the major announcement is viable.
"The US shale oil industry normally extracts 5-10 percent of the known shale oil reserves and raising this percentage depends on the advancement of technology," Ansari said.
The Bahraini minister and Ansari refused to be drawn into providing details about how much production Bahrain is likely to have in five years.
Shale oil production is a costly business and is far more expensive than conventional oil. In some cases, high cost makes production commercially not possible.
International consultants DeGolyer and MacNaughton, Halliburton, and Schlumberger are heading the project with Bahrain's National Oil and Gas Authority (NOGA).
Extensive work has already been carried out to evaluate in-place volumes. The first well in the drilling program is planned to produce in August, and over the next two years focus will be given to maximizing production and commercial efficiency, reported the Bahrain News Agency (BNA).
"Agreement has been reached with Halliburton to commence drilling on two further appraisal wells in 2018, to further evaluate reservoir potential, optimize completions, and initiate long-term production," Sheikh Mohammed added.
NOGA said that the next stage of development will focus on ensuring robust frameworks, data and terms are in place to facilitate further activities and commercial opportunities with international partners.
Analyst Stephen Brennock of broker PVM Oil said the find has "the potential to be a game changer" for the tiny Gulf kingdom.
"However, it is still early days and the reserves of the field have yet to be finalized. Moreover, it will be several years before these newly found supplies are brought online," Brennock told AFP.
The kingdom has also discovered natural gas estimated at between 10 trillion cubic feet and 20 trillion cubic feet, Sheikh Mohammed said.
Earlier on Wednesday, King Hamad bin Isa Al Khalifa received, at the Al-Sakhir Palace, Prince Salman bin Hamad Al Khalifa, the Crown Prince and Chairman of the Higher Committee for Natural Resources and Economic Security, following the discovery of oil and gas reserves, reported BNA.
He asserted that the landmark oil and gas find will pave the way for a new era in which the kingdom will carry on its development and progress, while maintaining the effective programs and initiatives aimed at increasing non-oil revenues and the ensuring the optimal use of financial resources.
