If you like energy stocks, you probably are aware of the next big trend in the business -- natural gas. The stuff has become an epicenter of attention recently as big players capitalize on attractive valuations and expansive opportunities.

Industrial warfare
Naturally, any company that joins this competition should be prepared to battle against entrenched giants such as Chesapeake Energy (NYSE: CHK) and Royal Dutch Shell (NYSE: RDS-A) (NYSE: RDS-B) -- two companies that have been dominating the business for decades. But things change. And today, investors should look at one of the giants in the exploration and production business, preparing to gain an even stronger foothold in the natural gas markets.

ExxonMobil (NYSE: XOM), which has already become the largest producer of natural gas in the United States by acquiring XTO Energy in 2009, is now expanding on that larger initiative, making smaller acquisitions to secure its foothold in the natural gas space.

After the acquisition of XTO for $34.9 billion, Exxon recently purchased natural gas firm Phillips Resources and related company TWP for $1.69 billion in a deal that will give Exxon access to 317,000 acres in the gas-rich Marcellus shale. The two firms, which will be added to existing XTO reserves, will produce combined year-end reserves of 228 billion cubic feet of gas.

The clash of the titans
Not one to be outdone, Shell is working on its own $10 billion liquefied natural gas project, which involves building a 600,000 metric ton floating structure for offshore drilling. This ground-breaking facility will be game-changing.

Chevron (NYSE: CVX), also among the fastest-growing LNG producers in the world, teamed up with Shell to start a $40 billion gas project in Australia. PetroChina (NYSE: PTR) agreed to buy a 50% stake in Canadian gas producer Encana's (NYSE: ECA) gas assets for $5.46 billion.

In response to all of this, the dominant Exxon is now going for smaller and smarter deals. This seems like a good strategy, especially considering its already massive scale.

Why is everyone going for natural gas?
Owing to the growing need for natural gas imports, the worldwide liquefied natural gas market is expected to approximately triple in volume from 2005 to 2030. Fool colleague Jim Royal believes that natural gas is all set to steal the show since the International Energy Agency expects consumption of natural gas to increase by 50% over the next 25 years. This is due to the shift of energy use to gas by large economies including China, Germany, and the United States. I couldn't agree more.

From an investment standpoint
In its first quarter this year, Exxon reported earnings of $10.65 billion -- a whopping 69% year-on-year leap and the highest since the third quarter of 2008. Its production in oil-equivalent volumes grew by 10.5%, thanks to the XTO deal.

But more importantly, Exxon's unlevered free cash flow stands at $19.6 billion. This was the fifth straight quarter that witnessed an increase in FCF. It implies that Exxon has ample cash to continue with its consolidation spree and still pay a healthy dividend to its investors. It has a payout ratio of 25% and a healthy yield of 2.4%. Chesapeake, with a payout ratio of 25.3%, offers a yield of 1.1%.

The Foolish bottom line
By acquiring these gas assets, the energy behemoth is just solidifying its dominance in the natural gas market. I suspect we'll see Exxon and its competitors going for more such consolidations in the not-so-distant future. These Big Oil components are betting huge on natural gas. Are you ready to bet on them?