By now, we've had enough second-quarter earnings releases from the oilfield-services folks to spot some emerging trends in this ever-more-important group. Schlumberger (NYSE:SLB) kicked off release season for the service sector with solid results and optimistic predictions about continued strength in the oil patch, with Weatherford (NYSE:WFT) and Halliburton (NYSE:HAL) each following up.

Now, Baker Hughes (NYSE:BHI) and its former subsidiary BJ Services (NYSE:BJS), have joined the party with their own intriguing opinions about where their business seems to be going. In addition to searching for oil in ultradeep waters around the world, they're also going to territory that even the most canny energy observers had just about written off: onshore North America.

Baker Hughes increased earnings by 8.5% to $379.3 million, or $1.23 per share. (The earnings included a $0.13-per-share litigation-related charge.) The company's revenue rose roughly 18%.

BJ Services, which competes with companies like Halliburton in the pressure-pumping arena, actually managed to lop about 16% off its earnings year over year, as a result of overcapacity and soft prices in the company's U.S. pressure-pumping operations. But at the same time, it guided analysts to expect a $0.54-to-$0.57-per-share range for the September quarter. The dart-throwers had been expecting about $0.50 for the quarter.

But the real key for the group, it seems to me, is that domestic producers -- and more and more majors, as well -- are finding natural gas in dense rocks and tight sands in places like Texas, Louisiana, Oklahoma, and western Canada. Many of these formations are sizable, and all are technologically challenging, thereby providing more work for the service sector. Indeed, the CEOs of both Baker Hughes and BJ prominently noted increased U.S. activity.

So with the international and domestic energy scenes both looking positive for the first time in ages, I'm here to redouble my urges that my Foolish friends keep especially close tabs on the oilfield services group.

Schlumberger and Weatherford have enough support among Motley Fool CAPS players to earn five stars. The others get four stars. How do they all stack up with you?

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Fool contributor David Lee Smith doesn't own shares in any of the companies mentioned. He does, however, solicit your questions and your CAPS participation. The Fool has a disclosure policy.