Oil is still within spitting distance of an all-time high, and natural gas is still well above long-term price trends. Yet the oil services ETF is off about 20% from its highs. Oh, those kooky markets. At least BJ Services (NYSE:BJS) had the luck to report strong earnings on a positive day for the sector -- it's just downright depressing to report good earnings when your whole sector is skidding.

The second-quarter report from this pressure-pumping specialist nearly mirrored that of the first quarter. Revenue was up 37% year over year (up 36% in the first quarter), and operating income climbed 87% (84% in the first quarter). Eerie, huh?

As we heard from Halliburton (NYSE:HAL) and Schlumberger (NYSE:SLB) last week, there's just no quick end in sight to the demand for pumping and production services. Rig counts in the U.S. keep climbing, and BJ Services is having a considerably harder time finding enough qualified workers than finding customers or pushing through price hikes.

What's more, when you consider the grief that companies like ExxonMobil (NYSE:XOM) and BP (NYSE:BP) sometimes get about their production figures, I don't think demand is going to let up as long as energy prices are this high. Consider Anadarko's (NYSE:APC) recent major purchases -- it's not buying Kerr-McGee or Western Gas with the intention of just sitting on those reserves and acreage.

Will energy prices drop at some point in the future? Yeah, probably. Will more competition and supply come into the service market to mop up this demand and these soaring rates? Sure. Will that happen next month? No. Next year? Maybe. And therein lies the problem -- figuring out the tipping point between the up-cycle and down-cycle is something that I don't think anybody has ever managed to do successfully -- at least, not more than once.

In the meantime, I'll just say again what I've said before about energy services -- the wild-and-crazy easy money has long since been made. That doesn't mean there isn't more money to be made, but it's going to be harder and riskier. Invest carefully, fellow Fools, lest the energy boom blow up in your face.

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Fool contributor Stephen Simpson has no financial interest in any stocks mentioned (that means he's neither long nor short the shares).