Report: US-Iran conflict disrupts OPEC+ production increase schedule, capacity review postponed to mid-November

The OPEC+ capacity review process has been delayed, due to the fact that the war between the US/Israel and Iran has disrupted the expansion plans of several projects in the Middle East, causing uncertainty in the estimation of future production potential for member states. This delay will directly impact the process of determining the alliance’s 2027 oil output quotas.

According to Reuters, citing two sources familiar with the matter, the deadline for completing this capacity review has been pushed back from the original end of September 2026 to mid-November.

Meanwhile, DeGolyer and MacNaughton, the US oil consultancy responsible for estimating the production capacities of OPEC+ members excluding Russia, Iran, and Venezuela, is expected to submit its report to OPEC by mid-November. This timeline in theory would still allow OPEC+ to discuss the results at the full alliance meeting in late November.

This delay has added further complexity to the already politically sensitive quota negotiations within OPEC+. The results of the independent capacity assessment will directly determine the approved production caps for each member country, and there are already clear disagreements among members regarding quotas, putting pressure on the stability of the alliance.

On Friday, the G7 decided to release 100 million barrels of emergency oil reserves, with a major release of diesel over the first 20 days. US oil prices once dropped over 5% before rebounding, and at the time of publication were down 3.33%.

The Middle East conflict has led to delays in projects intended to boost production capacity for some OPEC+ states, making it difficult for outsiders to accurately assess these countries’ actual oil production capacity. In addition, not all member countries have submitted the data required for the review.

OPEC+ launched this review process as early as the end of 2025, requiring a capacity audit for all members to serve as the basis for setting 2027 production quotas.

At the alliance’s full meeting this June, it reiterated the importance of completing the maximum sustainable capacity (MSC) assessment, making it clear that this would serve as an important reference for the 2027 output baseline.

On Friday, Russian Deputy Prime Minister Alexander Novak was cited by Russian state news agency TASS as saying that OPEC+ members are continuing to evaluate maximum capacity levels, but did not provide further comment on the delay.

The core purpose of this review is to provide an independent, updated evaluation of each member’s sustainable oil production capacity, a key reference point in all quota negotiations. If expansion plans are interrupted by war, the capacity assessment for affected countries will be weakened, which in turn will impact their future quota levels.

The impact of the assessment results on member interests is both direct and significant: countries found to have lower capacity may face pressure to have their quotas reduced, while producers that have successfully expanded their capacity will seek a larger share of production.

This logic has already been evident in recent alliance developments. The UAE, for example, long argued for an increase in its OPEC+ quota on the grounds of increased capacity, but after its requests were not fully satisfied, it exited the alliance in May this year.

According to previous reports, Iraq is also seeking a higher quota and has considered leaving OPEC. The current delay and uncertainty around the review is heightening these tensions further, and OPEC+’s internal cohesion faces a new test.