Given our perspective in the U.S., it's perhaps surprising to contemplate that the first commercial production of North Sea oil dates back to 1851, nearly a decade before the famous Drake Well was drilled in northwest Pennsylvania. That initial North Sea production occurred on Scottish shores when James Young extracted oil from boghead coal, or essentially oil shale.

The ultimate result was an oil and gas production zone offshore western Europe that has traditionally been referred to as the North Sea. In reality, that venue consists of several producing sectors, which are operated separately by the U.K., Norway, Denmark, and Germany. The area has been characterized by challenging weather and climactic conditions, and by ups and downs in the perceptions of its staying power as a meaningful producing horizon.

Wild weather woes
Volatile weather conditions have rendered the North Sea perpetually hazardous and have led to a stream of accidents and deaths through the years. Among the most noteworthy tragedies was the 1965 sinking of the Sea Gem, a rig being operated by -- you guessed it -- BP (NYSE:BP). The event, which took 13 lives, occurred as the rig was being moved off a newly discovered gas well in the West Sole field.

Major North Sea hydrocarbons finds have included the discovery of oil by what is now ConocoPhillips (NYSE:COP) at Ekofisk in Norwegian waters in 1969. More recently, in 2010, the Johan Sverdrup field, which is thought to contain up to 3.3 billion barrels of recoverable oil, was discovered on the Norwegian Continental Shelf. Norway's Statoil (NYSE:EQNR) and Canada's Nexen are among the companies currently active in the field. As you likely recall, the Canadian company is currently the object of a somewhat controversial $15.1 billion acquisition effort by China's CNOOC (OTC:CEO).

Unlike such other producing zones as the U.S. Gulf of Mexico and Brazil, output from the North Sea has evidenced significant decline curves. One estimate identifies 2001 as the peak year for production from the Norwegian sector. Oil output then reached 3.2 million barrels per day there, only to decline to 1.6 million daily barrels in 2010. Similarly, the British sector produced a high of 2.7 million barrels a day in 1999, then slid to 1.5 million barrels a day in 2010. More than half of the North Sea's current oil reserves and 45% of gas reserves are thought to exist offshore Norway.

Still life in that there sea
But don't count the North Sea out in contemplating your prospective energy investments. Just two weeks ago British Prime Minister David Cameron pledged at the Lord Mayor's Banquet in London -- from which I, unfortunately, was excluded -- that oil and gas operations in his country's portion of the venue would essentially be front and center in the U.K.'s "modern industrial strategy."

Houston-based Apache Corp. (NASDAQ:APA) clearly is one of the companies with an optimistic assessment of the North Sea's prospects. Nearly 10 years ago the company bought BP's Forties field in the North Sea for $630 million. And last year Apache agreed to pay $1.75 billion for ExxonMobil's (NYSE:XOM) North Sea assets, including the Beryl field.

Beyond that, just this week BP announced that TAQA, an Abu Dhabi government entity, would pay up to $1.3 billion for a "package" of its assets in the North Sea. And in mid-November, Royal Dutch Shell (NYSE:RDS.B) said that it had increased to 55% its stake in the Schiehallion field, west of the Shetland Islands, by acquiring Murphy Oil's (NYSE:MUR) 5.9% stake in the field. As further evidence that activity in the North Sea remains robust, Statoil recently announced that it had received permission from Norwegian government authorities to develop the Svalin field. The field, which is located about four miles from the Grane platform in the North Sea, is thought to contain about 75 million barrels of oil.

A Foolish takeaway
I've long been impressed by the operations of both Statoil and Apache. The former stands to benefit as worldwide oil exploration inevitably moves to colder climes, where it has demonstrated its mettle. The latter has shown a valuable ability to squeeze significant production from fields that other operators have judged to be "over the hill." I urge fools to keep tabs on both these solid companies.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.