Alberta has pushed back by three weeks the deadline for the final part of its updated oil and gas royalty regime after the technical aspects proved more complex than expected.

Premier Rachel Notley's New Democratic government released the fiscal terms for the energy sector in late January after months of intense study, and the province's most powerful industry was relieved that costs were not ratcheted up during the severe downturn.

The last part of the process, "calibration" of drilling and operating costs and rates of return, was due by the end of this month, but, at the request of the industry, Energy Minister Marg McCuaig-Boyd has delayed it to April 21.

Story continues below advertisement

"While work to establish the new calibrated rates has been progressing on schedule, my department officials and our industry participants have asked for some extra time to make sure the calibrated rates accurately reflect the state of the industry in Alberta, and to make sure all investment implications are clear and understood," Ms. McCuaig-Boyd wrote in a letter to participants in the royalty review.

Some investors and energy executives had expected major royalty hikes. But the government stuck to previous oil sands royalty rates as the sector coped with severely depressed crude prices. The NDP set a flat rate for new wells drilled outside the oil sands, easing industry fears.

The rates will be based on a host of factors, including a drilling and completion cost allowance formula, expected industry returns and the government's share of the value.

Industry officials believe that getting the formula right is more important than a few more weeks of study, said Chelsie Klassen, spokeswoman for the Canadian Association of Petroleum Producers.

"We've been working with the government during the whole calibration period and we came across a period of time where it required a bit more time to reflect on what had been developed," Ms. Klassen said.