It's an opportunity that's essentially missed by more than a few managements. I'm referring to the earnings post-release conference call, during which company leaders are afforded a superb opportunity to tell their story informatively and effectively to analysts and investors.

In oil-field services, among the calls and transcripts I've monitored during the current earnings season, my nod for an especially compelling effort goes to National Oilwell Varco (NOV 1.45%). Company President Clay Williams once again has done a yeoman's job of detailing Varco's progress in the context of prevailing or emerging trends in the energy sector.

Benefiting from four major energy trends
Williams said there are four specific movements in the energy industry that will continue to benefit National Oilwell Varco. For starters, the steady demand in floating drilling rigs for the deepwater continues unabated. Varco provides an array of equipment and components for the big rigs, where demand is being "underpinned by strong driller economics on these investments, good day rates, (relatively) low-cost rigs, quick delivery, and available financing," according to Williams.

Given these circumstances, Varco sold six newbuild deepwater drilling packages during the third quarter. That brought the total to 22 -- representing revenue of $9.5 billion -- for the year to date.

A trend toward floating production systems for the deepwater is also benefiting the company. As Williams said, "Over the past few years, we have invested in unique products required for (such) systems, including flexible risers, turret mooring systems, specialized deck, machinery pumps, sand handling and product equipment, and composite piping solutions."

An aging worldwide jack-up fleet and renewed interest in increasing shallow water production are also a boon for National Oilwell Varco. Not only is more than half of the worldwide marketed jack-up fleet more than 30 years old, but national oil companies in places like Mexico and Saudi Arabia are seeking to increase production from their continental shelves. As a result, the company sold 13 jack-up packages during the quarter, boosting its running total for 2013 to 42.

Products for the onshore, too
Varco isn't solely dependent on the offshore, however. Indeed, it's also a major provider of equipment for hydraulic fracturing in unconventional onshore plays. Obviously, most fracking to date has occurred in North America, about which the company's "outlook for ... 2014 is cautiously positive," Williams said. But beyond that, he noted that Mexico is adding new modern land rigs and Argentina has at least temporarily lifted its duties on imported rigs.

The Middle East, Russia, and Asia are have also become sites of strong demand for land rigs. Given that some will find work in emerging unconventional production, Williams said that "National Oilwell Varco is uniquely positioned to provide the tools required to bring the shale revolution to these new areas, an opportunity that we remain extremely excited about."

The company's competition
National Oilwell Varco obviously won't be the sole beneficiary of all these trends. As my Foolish colleague Dan Caplinger pointed out last week, the company faces competition from the likes of services giant Halliburton (NYSE: HAL),  along with conglomerate General Electric's (GE 8.28%) steadily expanding move into energy.

I'm inclined to agree that General Electric will play a progressively larger role in the industry. That's especially the case regarding subsea production, where the company has become a major factor and spending for equipment is growing exponentially.

For the same reason, however, I'm inclined to substitute Schlumberger (SLB 0.08%) for Halliburton as a more direct competitor to Varco. That's especially the case following the bigger company's recent formation with Cameron International of OneSubsea, a joint venture that is developing products, systems, and services for the subsea oil and gas market. The venture clearly will benefit from Schlumberger's research and development expenditures, which now amount to a whopping $1.1 billion annually.

But the deep pockets of General Electric and Schlumberger notwithstanding, subsea expenditures are projected to catapult from the $25 billion spent in 2011 to a projected $130 billion by 2020. As such, any number of companies stand to benefit meaningfully from the burgeoning phenomenon.

Foolish takeaway
All in all, and barring a nearly impossible-to-imagine protracted slowdown in oil and gas activity worldwide, National Oilwell Varco's unique mix of products and services almost certainly will continue to make its shares an excellent place for Fools to park investment pesos.