The US isn't the only one eating into OPEC's market share — Brazil and Guyana are hitting record oil production volumes

• OPEC+ has seen its oil market share fall to 51% this year, the IEA said Thursday.
• While US oil output has soared, Guyana and Brazil have also produced record volumes in 2023.

The Organization of Petroleum Exporting Countries and its allies have lost market share in 2023 in large part because of a US production boom, but Brazil and Guyana are also seeing banner years for crude output.

The International Energy Agency said Thursday that OPEC+ has seen its share of the oil market shrink to 51%, the lowest since 2016.

That comes as Brazil has seen its output jump 400,000 barrels a day to 3.6 million this year, according to Kpler data shared with Business Insider and depicted below.

Kpler's lead oil analyst Matt Smith said the country's production is about 800,000 barrels a day higher than 2017 levels.

"We expect production in 2024 to increase by a similar volume to what it did this year, and given that refining activity is fairly steady, higher production will translate into higher crude exports," he told Business Insider on Friday.

Meanwhile, Guyana's production has averaged 385,000 barrels a day this year, roughly 100,000 higher than last year, according to Smith.

And output is on track to average 600,000 barrels a day for the month of December, after a new stream of crude was brought online earlier this year at the Payara offshore oil development, he added.

And with more streams due in the future, Smith sees Guyanese production topping 1 million barrels a day in the years ahead.

All this presents a challenge to OPEC+, which has been announcing production cuts in a bid to control crude prices. Other countries have stepped in to fill the void that Saudi Arabia and others are leaving as they pull back on oil output, according to Smith.

Global crude prices have softened over the fourth quarter, however this week they remain on pace for their first weekly rise in two months.