In its Short-Term Energy Outlook, EIA said OPEC members produced 31.92 million bpd in 2018, about 150,000 bpd below the average output for 2017. Output is expected to fall to 30.88 million bpd in 2019 and 30.90 million bpd in 2020, S&P Global Platts reported.
OPEC's supply declines this year will be offset by a 2.4 million bpd oil supply increase from non-OPEC countries, particularly the US and Brazil, EIA said.
Total OPEC oil production averaged 31.38 million bpd in December, down 840,000 bpd from November. The latest Platts OPEC survey, released last week, found OPEC members produced 32.43 million bpd in December, down about 630,000 bpd from November.
The decline from November to December suggests that OPEC members began reducing oil production ahead of a supply-cut agreement with Russia and other producing countries. Under the agreement, these countries will cut production by 1.2 million bpd relative to October 2018 production levels. The cut began this month.
Oil production in Iran averaged 2.8 million bpd in December, down 100,000 bpd from November when US sanctions on Iranian crude exports were reimposed, with top buyers of Iranian crude getting temporary waivers. Iranian crude oil output has fallen by more than 1 million bpd since May 2018.
"EIA assumes that US sanctions on Iranian oil exports will remain in place through the end of the forecast period," the agency said. "Furthermore, the current forecast reflects an expectation that reduction-exemption waivers issued to eight countries to continue buying Iranian oil will not be extended past May 2019."