What's the best adjective to describe our current roller-coaster market? Brutal comes to mind, as do daunting, unhinged, and just plain absurd.

On that basis, as investors, we have two primary options: We can kiss Mr. Market goodbye until the economic storm blows over, or we can search for sectors and individual names that appear sensible, given a reasonable investment time horizon. The key, of course, is the time expectation, since few groups seem poised for a meaningful turnaround between now and, say, the December holidays -- of 2009.

From boom to bust … and back again?
Crude oil and natural gas prices went through a sudden and generally unexpected four-month free-fall. With their coffers full of cash, major integrated oil companies have been on my short list. Names I like -- given as much as a couple of years of brewing time -- include ExxonMobil (NYSE:XOM), BP (NYSE:BP), and ConocoPhillips (NYSE:COP).

But I also think there's potential in the bigger oilfield services stocks, companies like Schlumberger (NYSE:SLB) and Halliburton (NYSE:HAL). Oh sure, I recognize that drilling activity is destined to fall for a while. Indeed, Baker Hughes (NYSE:BHI) is looking for a sizable pullback in North America's working rigs in the short term. But I'm also among those who believe there'll be a bounce in the service companies' shares (along with crude prices) once the world's economies start to regain their sea legs.

About 18 months ago, with crude prices not far from their current level, I bought Schlumberger below $60 -- nearly $20 above where it is today. Although I subsequently sold, I still think Schlumberger is a solid company that does business in energy horizons throughout the world. Unless I miss my bet, $40 shares could set the stage for solid profits for those with the requisite amount of patience.

Last week, Halliburton, whose shares are down about 75% from their mid-summer high, held an analyst conference. While management admitted that hitting its earlier goal of 20% revenue growth will be a stretch -- to say the least -- it also noted that $1 billion in cash on the balance sheet, along with $1.6 billion in unused capacity on its credit facility, could represent the start of a meaningful acquisition effort.

I'll have more to say about Halliburton before long. In the meantime, though, let me suggest devoting some research to the oilfield service group.

Schlumberger and Halliburton are toting five and four Motley Fool CAPS stars, respectively. Have you weighed in with a thumbs up for either?

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Fool contributor David Lee Smith doesn't have financial ties to any of the companies mentioned above. He does, however, welcome your questions or comments. Try any of our Foolish newsletters today, free for 30 days. The Motley Fool has a well-oiled disclosure policy.