As far as I'm concerned, Irving, Texas, is pretty much the center of the universe this week. After all, Irving is the headquarters of ExxonMobil (NYSE:XOM), easily the world's largest corporation and a company that on Thursday reported record first-quarter earnings. And, hey, it's also the city where the EDS Byron Nelson Classic golf tournament is being contested this week.

At this point, we don't know who will get the biggest check on Sunday afternoon at Irving's TPC Four Seasons course. We do, however, know that ExxonMobil reported $9.3 billion, or $1.62 per share, in quarterly earnings, up 10% from the $8.4 billion, or $1.37 a share, the company recorded in the first quarter of 2006.

Exxon's strong earnings were largely attributable to its downstream -- or refining and marketing -- activities.  Indeed, the company's upstream exploration and production activities earned it $6.04 billion, or $342 million less than a year ago. That reduction related to lower realizations and to the reduced gas volumes that resulted from a warmer-than-normal winter in Europe.

At the same time, the downstream area contributed $1.91 billion to the quarter's bottom line, or $641 million more than a year ago. And the chemical segment checked in with $1.23 billion in earnings, up $641 million from the first quarter of 2006. The company's operating cash flow was $14.3 billion, down somewhat from last year's $14.6 billion.

Beyond the financials, however, I'm intrigued by the decline in ExxonMobil's daily production of crude oil and liquid natural gas: 5.7% in the U.S., 10.5% in Canada, and 7.1% in Europe. And while daily production increased in Africa and the Asia Pacific, Middle East, and Russia-Caspian regions, it will be interesting to follow these trends in the coming quarters. I must wonder whether declining production in our part of the world is explainable by weather, or whether it is a manifestation of permanently declining production.

There will, of course, be many important energy-related questions facing the U.S. citizenry and the world at large in the years ahead. Because many of the answers will not be particularly to our liking, I continue to suggest that Foolish portfolios include meaningful energy representation from among ExxonMobil, Chevron (NYSE:CVX), ConocoPhillips (NYSE:COP), and perhaps large energy services companies Schlumberger (NYSE:SLB) and Baker Hughes (NYSE:BHI).

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Fool contributor David Lee Smith owns shares of Schlumberger, but not of the other companies mentioned. He welcomes your questions or comments. The Fool has a disclosure policy.