Just call Apache a buying opportunity extraordinaire. Oil/gas exploration and development company Apache (NYSE: APA) has dipped about $10 from 52-week highs around $107.50 to about $97, due to oil's recent pull-back.

As a result, APA's p/e is down to about 15. A p/e of 15 may not seem that cheap, but given Apache's upside potential -- it is. Look for Apache to continue to achieve solid growth through internal investment and acquisitions. Apache has several key exploration discoveries set to enter development stage and will drill nine wells in Canada this winter as part of its oil shale operations.

Overall, analysts see Apache's oil and gas volumes increasing about 10%-12% in 2007 and 2008. Even better: the company believes it can generate double-digit production growth for the next decade. The Reuters F2007/F2008 EPS consensus estimates for APA are $7.54/$8.84.

In the 1989 motion picture "Dead Poets Society," actor Robin Williams, playing school teacher John Keating, inspires his new students to take advantage of opportunities presented in life, to "seize the day." Well, if Robin Williams will allow, now is the time to "seize the day with Schlumberger." (Pronounced: shlum-bur-ZJAY.)

Oilfield services company Schlumberger Ltd. (NYSE: SLB) is likely to benefit from growing demand for oilfield services technology, particularly in the high technology-dependent Middle East, Africa, and Eastern Europe regions.

Further, although North American margins have narrowed somewhat so far in 2007, international margins widened. Overall, in 2008 analysts see SLB's margins totaling 30% -- still a very healthy figure -- with revenue growth of 12-14%.

Having just shed its land-based oil exploration division, Pride International Inc. (NYSE: PDE) is now focusing only on offshore drilling for oil. According to a recent report from Goldman Sachs, this move puts PDE's stock price in a position to grow significantly even while the report claimed the outlook is down for offshore drilling as a whole.

According to the Goldman report, PDE's assets have been undervalued by the market, and there's a potential for backlogs to grow and increase profitability. This report expects profits, which have been growing steadily along with revenues, to grow even more over the next year as costs come down.

It's not just the Goldman analysts who have been paying attention to this stock. PDE has recently undertaken contracts to build two new drill ships, which will give the company much more range to seek out profitable drilling areas, and the company is widely seen as a potential acquisition target. Meanwhile, getting out of Latin America frees the company from dealing with leaders like Hugo Chavez or Evo Morales.

There was a big acquisition announced today [subscription required] in the world of oil and gas, as Marathon Oil Corp (NYSE: MRO) is picking up Canada's Western Oil Sands Inc. for $5.56 billion, plus assumed debt of $650 million.

The deal is going to give Marathon Oil a huge presence in one of the world's largest crude oil reservoirs, the Athabasca Oil Sands Project. The deal, which is scheduled to finalize during the fourth quarter of this year, is going to give Marathon control over 300,000 gross acres of oil sands.

There are lots of hopes riding on the future of oil coming out of the Canadian oil sands. While the cost of getting that oil out of the ground is much higher than the cost of normal oil exploration, there are several reasons why it is being viewed as very profitable. The primary reason is the close proximity that the area has to America, which is, after all, the world's largest consumer. Being the closest supplier to the world's largest consumer of oil puts companies in Canada in a very enviable position.