Fourth-quarter results from Canada’s biggest oil and gas companies will likely feature some surprises, as well as revisions to forward plans, given extreme volatility in commodity prices in the last three months of 2018, financial analysts say.

The parade of results begins Friday with Imperial Oil Ltd. and continues next Tuesday with Suncor Energy Inc.

During the quarter, U.S. benchmark West Texas Intermediate oil prices fell 16% from the previous period to average US$58.79 per barrel, but Canadian prices were much more severely impacted thanks to discounts blamed on full export pipelines, according to RBC Capital Markets.

Those discounts, which resulted in a 59% drop in the average price for bitumen-blend Western Canadian Select oil in the quarter and a 45% drop in the average price for lighter Edmonton Par crude, subsided to normal levels or lower in December after the Alberta government announced production curtailments beginning Jan. 1.

The price chaos will make it difficult to read too much into financial reports, which are likely to show buoyant returns for those oil and gas producers that also have refining operations, said RBC analyst Greg Pardy in a research note.

“Although fourth-quarter results will likely showcase the power of downstream (refinery) integration, we do not look upon them as indicative of the cash flow horsepower of our coverage group,” he said.

“This point reflects the severe dislocation of Canadian oil differentials across the complex during the fourth quarter — and downstream inventory distortions caused by the sharp drop in WTI. As such, we believe fourth-quarter results are truly backward looking in every sense of the phrase.”

About 25 operators who produce each more than 10,000 barrels of oil per day in Alberta have been affected by the government-mandated cuts.

Analysts also expect investor interest in prospects for crude-by-rail shipments, as smaller differences between Canadian and U.S. oil prices make that shipping option less financially attractive.

“Given how tight differentials have shifted, a number of conversations on the near-term Canadian outlook have centred around near-term rail expectations as spot pricing appears out of the money,” said Tudor Pickering Holt & Co. analysts in a report.

They added they expect rail shipping to continue at a good pace, however, because producers have signed deals with railways to add volume and will likely continue to use that capacity.

The fall in world oil prices last month could lead to cuts in capital spending plans announced in the fourth quarter by companies including mid-sized NuVista Energy Ltd. and Advantage Oil and Gas Ltd., the report says.