Southeast Asia's energy demand is expected to soar by more than 80 percent through 2035, says a new report from the International Energy Agency.

IEA, in its Southeast Asia Energy Outlook report released Wednesday, estimates that the region's oil imports will rise from the current 1.9 million barrels a day to slightly more than 5 million barrels a day by 2035, making it the world's fourth-largest oil importer after China, India and the European Union.

But the increasing reliance on oil imports -- 75 percent by 2035, compared with 44 percent today -- also makes the Southeast Asian countries more vulnerable to potential disruptions, IEA warns.

The analysis covers the 10 member countries in the Association of Southeast Asian Nations: Indonesia, Malaysia, the Philippines, Singapore, Thailand, Brunei, Myanmar, Cambodia, Laos, and Vietnam.

Combined annual spending on oil imports by Southeast Asian countries is projected to rise to $240 billion in 2035, equivalent to nearly 4 percent of the region's gross domestic product, IEA says. Its current oil import bill is $77 billion.

Oil import bills for Thailand and Indonesia are expected to be the highest, tripling to nearly $70 billion each in 2035.

"Southeast Asia is, along with China and India, shifting the center of gravity of the global energy system to Asia," IEA Executive Director Maria van der Hoeven said in a release.

IEA says that the region will need around $1.7 trillion of investment in energy infrastructure in the period to 2035.

Separately, a new report by Frost & Sullivan Tuesday says that Southeast Asia is on track to become one of the top locations for upstream oil and gas activities over the next five years.

It projects Southeastern Asia's oil and gas development market to earn revenues of $58.32 billion in 2017. That compares with revenues of $38.75 billion in 2012 and represents a compound annual growth rate of 8.5 percent.

The firm based its findings on current reserve discoveries and each Southeast Asian country's oil and gas development program. Malaysia and Indonesia show the greatest promise for deepwater and marginal fields' development, the report says.

But the report notes that insufficient government incentives in other Southeast Asian countries could deter investors.

Furthermore, investment opportunities in exploration and production in the region "are fraught with high risks as potential fields are found in remote areas," increasing production costs due to their location and lack of infrastructure, the report says.

"Technological enhancements, increasing gas demand, and rising oil prices have made marginal fields attractive for development, propelling the growth of drilling rigs and pipeline installations in Southeast Asia," said Frost & Sullivan Energy and Environmental Research Analyst Pradi Wigianto in a statement.