Turning to the first quarter. We had a strong quarter in terms of operating results. Production was very strong with 462,000 barrels a day, 4% above the equivalent quarter last year, and underpinned by a very strong quarter in both North America, which was driven by the shale being about 50% higher than a year ago and by Southeast Asia, which had a record gas production quarter delivering 136,000 barrels a day.
Cash flow was up 5% over the first quarter last year. Prices and volumes were up, but were offset to some extent by higher taxes and higher costs. Earnings from operations were $167 million for the quarter, reflecting higher prices, but also higher costs than a year ago and a higher DD&A rate, which Scott will explain in a moment. Costs were down from the fourth quarter last year when you may recall we had significant shutdown activity, particularly in the North Sea, but they're up on the equivalent quarter a year ago. This reflects in part increased activity since that time for instance, we've now got operations in Kitan in Australia, Jambi in Indonesia and Equion in Colombia.
In North America, we've also flowed through the new Pennsylvania impact fee, which this quarter includes a historical component. If we exclude the historical part of the impact fee, we continue to see a trend of reducing unit cost in the Shale business.
In the exploration portfolio, we found a significant oil leg in the Kurdamir-2 well in Kurdistan, which is sufficiently encouraging for us to plan an appraisal program on the structure. It's early days, but we are very encouraged by what we see so far. And in Papua New Guinea, our exploration wells continue to turn up what we expected, which is that the structures we are drilling tend to be full to spill. The latest well, Ketu-2, was another very positive result and is building on our gas resource exactly according to plan.