Exclusive-OPEC+ delays oil capacity review after Iran war disrupts expansion plans, sources say

By Alex Lawler and Olesya Astakhova

LONDON/MOSCOW, Oct 2 - An OPEC+ review to help to determine members’ 2027 oil output quotas has been delayed after the US-Israeli war on Iran disrupted projects to expand capacity across the Middle East, throwing estimates of future production potential into uncertainty, said two sources close to the matter. 

OPEC+, which comprises the Organization of the Petroleum Exporting Countries plus Russia and other allies, had ordered its production capacity review for all members in late 2025 before setting 2027 quotas, with completion due by the end of September 2026. 

The deadline has slipped, the sources said, with both saying the review is now expected to be completed by mid-November.

The OPEC producer group did not respond immediately to a request for comment. 

At its last group-wide meeting in June, OPEC said it affirmed "the importance of completing the maximum sustainable production capacity (MSC) assessment for all (member) countries to be used as reference for 2027 production baselines". 

PRODUCTION CAPACITY ESTIMATES IN FLUX

US petroleum consultant DeGolyer and MacNaughton is working on capacity estimates for OPEC+ members except Russia, Iran and Venezuela because they are under US sanctions, sources told Reuters in late 2025.

DeGolyer won’t submit its report to OPEC until mid-November, the two sources said. That timeline would still allow OPEC+ to consider the findings at its next group-wide meeting in late November.

DeGolyer and MacNaughton did not respond immediately to a request for comment sent before US business hours on Friday.

OPEC+ countries continue to assess maximum production capacities, Russian Deputy Prime Minister Alexander Novak was reported as saying by Russian state news agency TASS on Friday.

The Middle East conflict has delayed projects that were due to boost production capacity in some OPEC+ countries, complicating estimates of how much oil they will be capable of pumping. Not all countries have submitted the data required for the review, the sources said without naming the countries.

The uncertainty complicates a politically sensitive exercise for OPEC+, with production capacity estimates likely to influence how much individual members are allowed to pump.

UPDATED ASSESSMENTS KEY TO QUOTA NEGOTIATIONS

The review aims to provide an updated independent assessment of how much oil each member can produce sustainably, a key metric used in negotiations over output targets. 

Delays to planned capacity additions could affect assumptions underpinning those assessments and, potentially, members’ future quotas.

Countries whose assessed capacity is lower could face pressure for lower quotas while producers that have expanded capacity might seek higher allocations.

The United Arab Emirates, which had pushed for a higher quota from OPEC+ to reflect rising production capacity, left the alliance in May.

Iraq is also seeking a higher quota and has considered leaving OPEC, sources told Reuters in June.

(Reporting by Alex Lawler and Olesya AstakhovaAdditional reporting by Ahmad GhaddarEditing by Dmitry Zhdannikov and David Goodman)