Fifty new oil and gas fields in Southeast Asia, holding a combined four billion barrels of oil or equivalent, are likely to be approved for development between 2018 and 2020, according to industry data powerhouse Rystad Energy.

Natural gas is expected to account for 85% of the new production, with Vietnam delivering the biggest increase this year.

“Strong economic growth has led to burgeoning domestic gas demand throughout the region,” said research analyst Readul Islam. “The resulting uptick in local gas prices as well as the pollution profile of the fuel compared to alternatives means both operators and governments are incentivized to push natural gas projects.”

The projects will soak up US$28 billion in capital investment. Malaysia is expected to develop 37% of the new resources and draw 42% of the new investment, while Indonesia accounts for the largest number of new fossil fields, at 19.

Out of the 50 projects, Islam said some of the biggest pieces of new infrastructure are already in place, and several projects are “later phases of earlier developments,” Rigzone reports.