HOUSTON, May 5 (Reuters) - As Big Oil returns this week

to the industry's annual showcase for offshore energy projects

and equipment in Houston, deepwater discoveries off Guyana,

Namibia and the U.S. Gulf Coast will take the spotlight.

Offshore exploration had dimmed after the U.S. shale boom

ushered in new and cheaper-to-tap supplies of oil, and as past

offshore cost overruns pushed deepwater projects onto the

industry's backburner.

Newer deepwater projects have the attributes oil and gas

companies are looking for: longer-term production, lower

breakeven costs, big resource potentials and lower carbon

emissions, said Pablo Medina, head of new ventures at energy

consultants Welligence.

"Deepwater is back in vogue," Medina said.

Capital spending on all-new deepwater drilling is poised to

hit a 12-year high next year, predicts consultancy Rystad

Energy. Investment in all-new and existing deepwater fields

could hit $130.7 billion in 2027, a 30% jump over 2023, it said.

"The return of offshore and deepwater operations is going to

be a big topic at OTC, and Namibia is going to be talk of the

show," said James West, senior managing director at financial

firm Evercore, referring to the recent series of oil finds off

the west African coast.

FASTER PAYBACK PERIODS

With crude oil prices above $70 a barrels, energy producers

can expect a return on their multi-billion-dollar deepwater

projects in six years, a relatively short period considering the

wells' longer lives compared with shale, explained Matt Hale,

vice president of supply chain research at Rystad, at the Rystad

Energy Forum in Houston last month.

Deepwater resources also offer lower carbon emissions

intensity than shale and other tight oils, averaging 2kg of

carbon dioxide per barrel less than shale, Hale said. That

appeals to investors seeking safer bets as environmental

regulations tighten.

Enthusiasm for offshore has climbed with discoveries and

technology breakthroughs. Namibia's Mopane is forecast to hold

as much as 10 billion barrels of oil, Portuguese oil company

Galp Energia said last month.

Chevron ( CVX ) and TotalEnergies have made a breakthrough in

ultra-high pressure environments with their Anchor project in

the Gulf of Mexico, the world's first to operate at

once-unfathomable 20,000 pounds per square inch (psi) pressures.

The Anchor platform is preparing to start production off the

Louisiana coast, and at its peak will produce up to 75,000

barrels per day (bpd) of crude and operate for 30 years.

The Stabroek block off the coast of Guyana has demonstrated

the potential for low cost production that rivals the best

deepwater fields elsewhere.

Over the next six years, more than half of its recoverable

resources are expected pump at a breakeven price of less than

$30 per barrel, according to Rystad. That is comparable to the

breakeven on about 80% of deepwater recoverable resources off

Norway, Rystad estimates.

Renewed interest in deepwater has boosted demand and results

for offshore drilling contractors. Rates for some vessels have

surpassed $500,000 a day and contract durations are lengthening

as vessel supply dwindles.

"We are reaching this crescendo over the next 18 months or

so where the (deepwater rig) market will level out," said Leslie

Cook, upstream supply chain analyst at consultants Wood

Mackenzie.