As 900 more jobs vaporized in downtown Calgary this week, oilpatch offices are growing accustomed to news of workplace contractions.

Oilfield services company Tervita was the latest company to announce cuts. It is reducing its corporate headcount by 15 per cent because of the "prolonged downturn in the energy markets."

The layoffs are expected to free up room in downtown offices of many oil companies.

"They're calling them ghost towers," said Deborah Yedlin, the Calgary Eyeopener's business commentator. "The spaces are leased but no one is in them."

'Everybody's in survival mode.' - Deborah Yedlin

Yedlin says the sub-lease market has grown considerably since oil prices started swan diving last year, with energy companies renting out their empty offices at cost.

"They're just trying to move it, they just want to cover their operating costs."

Yedlin says she wasn't surprised to hear about the latest cuts — 500 from Conoco Phillips and 400 from Penn West on Tuesday.

"Clearly, companies have to start making decisions. They have few levers at their disposal — whether it's capital expenditures, decreasing dividends," said Yedlin.

"Everybody's in survival mode."

She says one the biggest challenges companies are facing is the fact that so many of the veteran oilpatch players have retired.

"It's new territory for a lot of people unless they have individuals on their boards that can offer them guidance who have been through this before," said Yedlin.