CHICAGO: Dangerous and difficult oil fields that looked like goldmines when crude fetched more than $100 a barrel have turned into money pits as oil crashes to multiyear lows.

Collapsing oil prices not only shrink profits for producers and imperil dividend payouts prized by investors, they can cripple a company’s future growth by starving it of cash needed to find, drill, assess and equip discoveries.

A spending halt in deep-water fields and Canada’s oil sands could disrupt the chain of new projects needed to keep the world supplied as older wells dry up.

For the biggest explorers, the impacts of slumping prices are dramatic. Every $10 price drop erases $2.8 billion in annual cash flow for Exxon Mobil, according to analysts at Barclays.

For Chevron, which is more crude-dependent than its bigger rival, a $10 change translates to $3.85 billion in cash flow.

“Because of their long lead times, once canceled or postponed, oil sands and deep-water projects cannot be brought online at short notice in response to rising prices,” CEO Andrew Hall said in a Jan. 2 communique to investors in his Astenbeck Capital Management commodity funds. “This sets up the potential — if not the inevitability — for supply shortfalls in the future.”

Energy explorers who committed to hundreds of billions of dollars in oil projects from Brazil to Scotland to Oklahoma during the past five years now are working to trim costs and delay contracts.

Crude’s tumble to less than $50 a barrel, the lowest prices since 2009, is prompting budget cuts and layoffs from the rig floor to the steel mills that make piping for wells.

Explorers are expected to cut spending by 17 percent this year to $571 billion, James Crandell, a Cowen and Co. analyst, said in a note to clients.

Crandell, who has been tracking oil-industry capital spending since 1982, said the estimate assumes an average crude price of $70 a barrel. If prices turn out to be lower, spending will decline more, he said.

An oil-market rebound that would bail out the most ambitious and expensive ventures seems increasingly unlikely. Worldwide demand growth is faltering, worsening a US supply glut that hasn’t been this big at this time of year in three decades. The excess — a result of the unprecedented production boom in US shale rock formations — may take “months or years” to be absorbed, said UAE Energy Minister Suhail Al-Mazrouei.

Brent crude futures, the benchmark contract for more than half of the world’s oil, recently touches a 5 1/2-year intraday low of $49.66 a barrel. The 6-month slump is the longest since the global financial collapse of 2008 that slashed demand for petroleum-based fuels.

Oil was trading for $125 a barrel when drilling began on Noble Energy’s Gunflint prospect in May 2008 about 70 miles off the Louisiana coast. Now oil is 60 percent less valuable as the Houston-based company begins installing a sprawling network of pressure-control devices and valves more than a mile beneath the sea surface that will start pumping crude by the middle of 2016.

Reba Reid, a Noble spokeswoman, didn’t respond to telephone messages left at her office.

At another deep-water Gulf of Mexico project, known as Stampede, Hess is forging ahead with a $6 billion effort to unlock as much as 350 million barrels of crude starting in 2018. When directors at Hess and three partner companies formally greenlighted Stampede in October, oil was trading for more than $80 a barrel.

Every $10 drop in the price of a barrel of crude erodes Hess’s cash flow by $850 million, according to Barclays.

Lorrie Hecker, a spokeswoman for New York-based Hess, declined to comment on whether Stampede will be postponed or redesigned to account for the slump in crude markets. Details on the company’s 2015 spending and drilling plan won’t be released until later this month, she said.

“Stampede is an important long-term part of our portfolio that we intend to move forward,” Hecker said in an e-mailed message.

Even before the oil market collapse began in late June, developers in Canada’s oil sands were already doubting the viability of new projects after a $250 billion building spree over the preceding eight years.

France’s Total put its joint-venture project with Suncor Energy on hold in May, citing escalating construction costs. That followed a 2013 cancelation by the companies of their C$12 billion Voyageur oil-sands upgrader.

In September, Norway’s Statoil delayed work on the 40,000 barrel-a-day Corner oil-sands development. Devon Energy said in November that a decision on how to proceed with its Pike oil-sands venture with BP will be made by the end of 2015.

In Brazil, home to the Western Hemisphere’s biggest oil discoveries in a generation, falling prices are close to slamming shut the profitability of those reserves. Petroleo Brasileiro, or Petrobras, said in a statement yesterday that it needs a minimum price of about $45 a barrel to justify tapping the string of mammoth offshore discoveries that captivated the global energy industry in 2007.

(c) 2015, Bloomberg News.