Chevron, one of the companies that discovered the Hibernia oil field and the holder of significant ownership stakes in Newfoundland and Labrador's offshore oil industry, is slashing its workforce in St. John's as part of a restructuring prompted by plunging oil prices.

Sources say the company will eliminate 60 per cent of the workforce at its Atlantic Canada office in St. John's, or roughly 20 jobs.

Some will be relocated to Calgary, sources say.

Leif Sollid, a senior Chevron communications official, told CBC News that assessments and planning for the restructuring have been going for several months.

Hibernia platform CBC

Chevron Canada Resources has a 26.9 per cent non-operated working interest in the Hibernia field off the east coast of Newfoundland and Labrador. (CBC)

"Chevron Canada is restructuring its organization to establish a competitive foundation that will position the business to deliver profitable long-term growth in our key focus areas of Alberta, British Columbia and Newfoundland and Labrador," he said in an email.

Sharp decline in revenues

Sources say Chevron is reducing its presence on the east coast as lower oil prices have taken a toll on the parent company. California-based Chevron Corp. has reported revenue declines of more than 50 per cent from a year ago.

The company is also stinging from an aggressive exploration program in the deepwater Orphan Basin off Newfoundland that turned up less-than-stellar results.

"Chevron came up dry while Statoil hit the mother lode," said one source familiar with the industry, referring to Statoil's Bay du Nord discovery in the Flemish Pass Basin.

Another source downplayed the likelihood of a dramatic downsizing in St. John's, explaining that Chevron continues to have "major production and explorations interests" in the province.

Hebron project at Bull Arm on June 10, 2015

Construction of the Hebron oil platform at Bull Arm is ongoing, and the project is still on track to produce first oil by the end of 2017. Chevron Canada Resources holds a 26.6 per cent non-operated working interest in the project. (CBC)

A statement from the provincial Department of Natural Resources said "we have been advised that Chevron's ongoing business and community investments in the province will continue."

Chevron did not reply to specific questions about its operations in this province, including the number of employees at its St. John's office.

The Calgary Herald reported last week that Chevron was preparing to eliminate one in five of the positions at Chevron's Calgary offices, where there are 800 employees.

The company also announced late last year it was shelving plans to drill a deepwater well in Canada's Beaufort Sea because of plunging oil prices.

Spending cuts throughout energy sector

There have been sharp spending cuts throughout the energy sector as companies navigate their way through lower prices, and Newfoundland and Labrador has not been immune.

Husky Energy, for example, announced in December it was deferring the final investment decision on its offshore West White Rose oilfield extension project for a year.

Chevron has played a significant role in the energy sector off Canada'a east coast for many years, and according to its website, discovered the Hibernia field in 1979.

This discovery was the catalyst that launched Newfoundland and Labrador's offshore energy sector.

Chevron holds a 26.9 per cent non-operator working interest in the Hibernia field, and accounts for most of the company's crude oil production.

Chevron holds a similar ownership stake in the Hebron field development project, which is expected to begin production in two years southeast of Hibernia.

Chevron also owns a one per cent interest in the Terra Nova project.

According to its website, Chevron will also be involved in exploratory drilling in the Flemish Pass Basin later this year.

"Chevron Canada is committed to responsibly developing Canada's energy resources and will continue to make significant investments going forward," Sollid wrote.