The major oil companies are on a buying binge, suggesting that it may be quicker, easier, and more economical to grow reserves with a checkbook than a drill bit.

The latest integrated buyer to purchase new properties is Italy's Eni (NYSE:E), which is snapping up First Calgary Petroleums for $868 million. Rather than picking up a slug of Canadian oil-sands properties, as you might expect, however, the deal will yield the addition of about 190 million barrels of oil equivalent (boe) -- mostly in Algeria -- to Eni's reserves.

According to the Italian company, which has been buying hot and heavy during the past 18 months, the primary property in the acquisition is expected to begin producing in 2011; it should reach 30,000 boe a day the following year. Eni is apparently paying a nearly 60% premium to the 30-day average for the Canadian company.

Eni's acquisition coincides with ConocoPhillips' (NYSE:COP) announcement that it'll pay as much as $8 billion for a 50% interest in Australia's Origin Energy's coal-bed methane project. Under the terms of the agreement, Conoco will pay $5 billion up front, followed by a string of $500 million payments and a $1 billion fixed payment near the end of 2010. Origin will operate the coal seam production, while Conoco will handle the refinery portion of the venture.

Those two newly announced deals follow another pair of recent pacts between BP (NYSE:BP) and Chesapeake Energy (NYSE:CHK). And then there's the recent deal in which Royal Dutch Shell (NYSE:RDS-A) (NYSE:RDS-B) would, um, shell out nearly $6 billion for Canada's Duvernay Oil.

I'm particularly following BP, which has struggled with a string of stumbles in the past few years. With its new acquisitions and its surprising settlement last week of the sticky situation surrounding its TNK-BP Russian venture, BP's luck may finally be changing.

For related Foolishness:

For three energy stocks Motley Fool analysts believe will profit from "The Next American Oil Boom," check out our brand-new free report. You'll get three stock ideas from top analysts, plus some straight talk on our oil "crisis." Click here to get it free!

Fool contributor David Lee Smith doesn't own shares in any of the companies mentioned. He does, however, welcome your questions or comments. Chesapeake Energy is an Inside Value recommendation. The Fool has a thrifty disclosure policy.