Royal Dutch Shell and Total reported strong increases in first-quarter earnings as higher oil prices and rising production accelerated recovery at Europe’s two largest energy groups.

Shell’s profits jumped by 41% to the highest level since oil was trading at $100 per barrel before the 2014 crash, while Total’s were up 13%.

Meanwhile ConocoPhillips, the U.S. exploration and production company, returned to profit during the three months to March and increased its output projections for the year in a further sign of confidence returning to the sector.

The results followed buoyant numbers from Statoil of Norway on April 25, while ExxonMobil and Chevron are expected to follow suit on April 27, after a quarter in which oil prices averaged almost $67 per barrel, 25% higher than a year ago.

Brent crude, the international benchmark, has since risen further to four-year highs above $75 per barrel, promising even stronger cash flow during the second quarter for the world’s biggest energy groups.

As well as harnessing higher prices, they are keeping a tight rein on costs, which have been cut by a third or more since 2014.

“These companies are more profitable now than they were at $100 per barrel,” said Alasdair McKinnon, fund manager at Scottish Investment Trust, which owns shares in Shell and Total.

“They have gone from pariah stocks with negative cash flow and uncovered dividends to positive cash flow and covered dividends in a relatively short space of time.”

There was disappointment from some investors that Shell’s results were not stronger as a one-off tax bill and losses on hedging activities put a dent in otherwise bullish numbers. Shares in the Anglo-Dutch group fell 2% on the morning of April 26.

Another source of frustration was Shell’s refusal to set a firm timetable for launching a $25 billion share buyback program, although Jessica Uhl, CFO, said the group remained committed to fulfilling the pledge between this year and 2020.

Shell would strike a balance, she said, between reducing debt and improving shareholder returns, while maintaining a disciplined approach to capital expenditure.

The group’s debt ratio fell to 24.7% at the end of March, from 28.3%a year ago, and Uhl said there was a “clear line of sight” for it to keep falling to 20%.

As well as higher oil prices, debt reduction has been aided by near-completion of the $30 billion asset disposal program launched after Shell’s acquisition of BG Group two years ago.

The group said it had completed $26 billion of divestments with a further $6 billion announced or in progress.

A range of mostly mature or higher-cost assets have been sold, from North Sea oilfields to Japanese refineries, sharpening Shell’s focus on priorities such as deepwater resources off Brazil and liquefied natural gas.

Shell reported earnings on a current cost of supply basis—the measure tracked most closely by analysts—of $5.3 billion, excluding exceptional items, up from $3.8 billion a year ago.

This was narrowly ahead of analysts’ consensus forecast, but cash flow from operations was weaker than expected at $9.4 billion. Production rose 2% to 3.8 MMbbl/d.

Total beat analysts’ expectations with adjusted net income of $2.9 billion, up from $2.6 billion a year ago.

Production rose more than 5% to a record 2.7 MMbbl/d and was likely to exceed the group’s target for 6% growth over the full-year as new projects and newly-acquired assets begin contributing.

ConocoPhillips, the largest “pure-play” exploration and production company in the U.S., also beat Wall Street forecasts with adjusted earnings, excluding one-off items, of $1.1 billon, compared with a $200 million loss in the same period last year.

Its production, excluding Libya, rose 4% to 1.2 MMbbl/d, with growth of 20% from U.S. onshore shale resources.