Brownfield Output Decline Accelerates, says IEA

By Seher Dareen
Tuesday, September 16, 2025

The decline in output from mature global oil and gas fields is accelerating amid greater reliance on shale and deep offshore resources, the International Energy Agency said on Tuesday, meaning companies need to invest more just to keep output flat.

The IEA, which advises industrialised countries, is under fire from U.S. President Donald Trump's administration for a recent shift to focus on clean energy policy. A 2021 IEA report said there should be no investment in new oil, gas and coal projects if the world was serious about meeting climate targets.

Tuesday's report warns that without continued investment in existing fields, the world would lose the equivalent of Brazil and Norway's combined oil production each year, with implications for markets and energy security.

"Only a small portion of upstream oil and gas investment is used to meet increases in demand while nearly 90% of upstream investment annually is dedicated to offsetting losses of supply at existing fields," IEA Executive Director Fatih Birol said in an IEA statement.

"Decline rates are the elephant in the room for any discussion of investment needs in oil and gas, and our new analysis shows that they have accelerated in recent years."

Drawing on data from about 15,000 oil and gas fields around the world, the IEA said that after reaching peak production the average annual decline in output was 5.6% for conventional oil fields, and 6.8% for conventional gas fields.

A halt in upstream investment would cut oil supply by 5.5 million barrels per day each year, the IEA said, up from just under 4 million bpd in 2010. The 5.5 million bpd figure is roughly equal to Brazil's and Norway's output combined.

The decline for natural gas has risen to 270 billion cubic metres per year from 180 bcm, it said.

The IEA has been at odds with producer group the Organization of the Petroleum Exporting Countries over its 2021 report and its forecasts that call for a relatively swift energy transition and a peak in oil demand by 2030.

OPEC, in a statement on Tuesday, criticised the IEA's report, saying the agency had not referenced how its 2021 report and peak oil demand forecast had discouraged investment and contributed to uncertainty about long-term demand.

"In contrast to the IEA's U-turning on this important issue, OPEC has consistently advocated for timely investments in the oil industry to account for decline rates and meet growing demand," OPEC said.

(Reuters)

Categories: Technology Offshore Energy Drilling Subsea Industry News Activity Production Brownfield Offshore Oil

Related Stories

Valaris Secures $600M in New Contracts as Backlog Rises to $4.8B

ADES Lands New Offshore Drilling Rig Deals in Angola and Indonesia

Eni, Petronas JV Brings Indonesian Offshore Gas Field Online

Damaged Tanker Leaks Oil Across UAE Waters as Spill Widens

Energy Drilling Lands $87M Drilling Job Offshore Malaysia

Oil India Discovers Gas in Shallow Waters of Krishna-Godavari Basin

Oil Markets Brace for Years of High Prices as Iran War Drags On

Yinson Production Raises $1.46B to Refinance Agogo FPSO

Oil Climbs on US Storm Threat, Saudi Attack Risks

Saudi Oil Lifeline Shut After Attack as Red Sea Threat Grows

Current News

Tender-Assist Rigs: Southeast Asia’s Quiet Workhorses Head for Full Utilization

Aker Solutions Lands Major Role in Qatar’s Offshore Oil Field Revamp

TotalEnergies Inks 15-Year LNG Supply Deal with China's Jiangsu Guoxin

Baker Hughes Sets Up Global Network to Bolster Mature Oil and Gas Fields Production

Valaris Secures $600M in New Contracts as Backlog Rises to $4.8B

Production Restart at Australian Offshore Fields Boosts Jadestone's Oil Output

Aramco Targets Hormuz Bypass with East-West Pipeline Expansion

ADES Lands New Offshore Drilling Rig Deals in Angola and Indonesia

Shell to Exit Australia's North West Shelf Project in $1.45B Deal with XRG

Aramco Third Quarter Profit Up 35% Despite War Disruptions

Subscribe for AOG Digital E‑News

AOG Digital E-News is the subsea industry's largest circulation and most authoritative ENews Service, delivered to your Email three times per week

https://accounts.newwavemedia.com