As with most companies, for Diamond Offshore (NYSE: DO), there are both short- and long-term considerations. In the latter time frame, the company appears to be one of the more solid participants in the field we broadly label "oilfield services." More immediately, however, its results have been hit by a one-time tax charge and the higher expenses that have been working their way across the energy sector.

In the quarter, the company earned $164.9 million, down 25.5% from the $221.4 million in the comparable period a year ago. The per-share number was $1.19, compared to $1.60 in the December 2006 quarter. The latest quarter included a $0.42 charge related to previously untaxed earnings from a foreign operation. Revenue was up more than 15% from a year ago.

Diamond constitutes a tale of two companies, with its smaller jack-up segment not faring as well as the other types of units because of overcapacity and a Gulf of Mexico slowdown. Indeed, jack-up dayrates were about flat in the quarter, at an average of about $115,000, and a utilization rate that markedly slipped to 63%, from 81% in the December 2006 quarter.

At the same time, the company's deeper-water "intermediate semis" and "high specification floaters" are doing better. Those rigs have experienced dayrate expansions in the past year. And for those with an interest in probing what I believe is a solid company, Diamond's website contains a rig report that provides all manner of intriguing details on its various rigs, their dayrates, general operating costs, and contract status.

Beyond that, Diamond Offshore, whose board has declared another special cash dividend of $1.25 a share, joins such other members of the services set as Schlumberger (NYSE: SLB), BJ Services (NYSE: BJS), Halliburton (NYSE: HAL), and Baker Hughes (NYSE: BHI) in reporting results that frankly have been all over the map. Diamond's deepwater-drilling running mate, Transocean (NYSE: RIG), will tell us about its quarter later in the month.

Diamond's shares have slipped nearly 8% just in this not-yet-completed week. Given the company's crucial role in the worldwide search for oil and gas, my approach is to recommend that Fools keep an eye on its price movement, and as the slide appears to abate, consider slowly building a position in the company.

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Fool contributor David Lee Smith doesn't own shares in any of the companies included above. He does welcome your questions or comments. The Motley Fool has a disclosure policy.