* Oil prices surge due to Iran conflict, boosting profits

* Analysts revise Chevron ( CVX ), Shell earnings estimates

upwards

* Middle East disruptions may hurt oilfield-service

companies

By Sheila Dang, Stephanie Kelly and Amanda Stephenson

HOUSTON, March 26 (Reuters) - As Big Oil executives

gathered this week and discussed the biggest-ever disruption to

global energy supplies due to the war in Iran, there was one

impact they did not address publicly: the multibillion-dollar

windfall they will make because of soaring prices for the energy

they sell.

Global benchmark Brent crude has so far averaged around $97

per barrel in March, up 33% from the $69 average in February and

even more from $65 in January. The U.S.-Israeli war on Iran that

started on February 28 has halted a fifth of the world's supply

that passes through the Strait of Hormuz waterway. Natural gas

prices in some parts of the world have risen even more.

The situation could resemble 2022, when Big Oil broke

records for profit after Russia's February invasion of Ukraine

rocked energy markets. That year, oil companies rewarded

shareholders with record dividends and share repurchases. Public

outrage sparked calls for windfall-profit taxes.

"The first quarter is going to be phenomenal for these

companies. I don't think there's any way around that," said Leo

Mariani, a senior research analyst at Roth Capital Partners.

U.S. shale producers and other companies without major

operations in the Middle East should gain the most, benefiting

from higher prices without costs associated with shut-in

production, stranded tankers or expensive repairs to war-hit

facilities. Still, executives said the big profits will probably

not boost their planned capital spending on new production.

CHEVRON ( CVX ), SHELL, EXXON MOBIL STAND TO MAKE BILLIONS

In the past month, six analysts covering Chevron ( CVX )

revised their projections for the U.S. oil major's first-quarter

per-share earnings, raising estimates by an average of about

40%, according to LSEG data. Three analysts covering

London-based Shell increased their net profit estimate

for the three-month period by an average of 15%.

The consensus Wall Street estimate for Exxon Mobil's ( XOM )

full-year per-share earnings has been revised up about 4% from

before the war, smaller than forecasts for other companies. This

could be because Exxon, the biggest U.S. oil company, has more

production exposure to disruptions in the Middle East, said

Stewart Glickman, director of equity research at CFRA Research.

Four analysts covering Exxon increased their earnings

estimate in the past month, while three revised them down,

according to LSEG data.

Exxon will publish its first quarter earnings snapshot next

month, detailing factors that impacted earnings. Shell will

release a quarterly update note on April 8 detailing the

expected financial effects from the conflict. Part of Shell's

Pearl GTL (gas-to-liquids) facility in Qatar was damaged in

attacks this month.

Chevron ( CVX ) produced 4 million barrels per day in the fourth

quarter and the average Brent spot price was $64 per barrel.

Assuming a price rise of $33 per barrel, additional revenues in

March would add up to roughly $4 billion, according to a Reuters

calculation.

Exxon produces close to 5 million barrels of oil per day.

Assuming the same price rise per barrel, additional revenues in

March would add up to about $5.1 billion.

Timing effects including hedging mean some cash flow and

earnings might not appear in company results until the second

quarter or later.

The war has also upended the gas market. In Asia, liquefied

natural gas prices have skyrocketed 143% since the war began.

Some upside may be muted by lost oil and gas output from

facilities in the Middle East, and the additional cost of

meeting obligations to customers by rerouting oil and gas from

elsewhere. Some facilities have sustained damage from Iranian

missile and drone attacks.

The halt to exploration and production activities in the

Middle East, meanwhile, could hurt oilfield-service companies,

said James West, head of energy and power research at Melius

Research.

SLB gets 34% of its revenue from the Middle East and

North Africa region, while Weatherford International ( WFRD ) gets 44% of

its revenue from the region, West said.

Weatherford did not respond to a request for comment. Exxon,

Shell and Chevron ( CVX ) declined to comment. SLB referred to a

previous statement that said revenue for the first quarter would

be lower than expected and that the company expects to incur

additional costs resulting in an impact of approximately 6 to 9

cents of earnings per diluted share.

U.S. SHALE PRODUCERS COULD SEE BIGGEST GAINS

The consensus of Wall Street estimates projects Diamondback

, a U.S. shale producer with no international assets,

will report first quarter earnings of close to $3 per share, 28%

more than estimates made before the war, Glickman said. Analysts

appear to expect a similar boost for the full year and have

raised their projections of Diamondback's per-share earnings by

22% from estimates before the conflict, he added.

"It suggests company estimates are baking in longer-term

effects even as the (Trump) administration is trying to provide

confidence to the market that traffic will flow through the

Strait of Hormuz again," Glickman said. Diamondback did not

respond to a request for comment.

"The oil industry all depends on the price. The price has

increased, every oil company is benefited," said Anil Agarwal,

founder of Cairn Oil & Gas, a private oil and gas producer in

India.

Bumper first-quarter profits, however, are unlikely to lift

capital spending plans or trigger investment in boosting

production, said Jeff Lawson, executive vice-president with

Cenovus, one of Canada's largest oil sands companies.

"I don't want to rely on the oil prices we've just seen,

because it feels like a horrible blip," Lawson said.

Lawson did not speak to what the prices could mean for

Cenovus' first-quarter profits, but he said a short-term price

spike is unlikely to result in any Canadian oil sands producer

sanctioning a new project.

"Oil's going to go up, oil's going to go down, and I need to

show five to seven years out on a new project that it works," he

said.