Shell's earnings have dropped by 74 percent in the fourth quarter from the same period a year ago, on a mix of higher exploration costs, lower production, and worse refining margins.

The company, which warned on Jan. 17 weaker figures were coming, also had more one-time gains in 2013. Net profit for the quarter was $1.78 billion (130 billion euros), versus $6.73 billion a year earlier.

The earnings report, the first featuring new Chief Executive Ben van Beurden, noted that production was down 5 percent to 3.25 million barrels per day. Shell said 2 percentage points were due to wells shut in Nigeria for security reasons, Shell said, and the rest due to other maintenance and "asset replacement activities" — old fields fading faster than new projects came online.