This year has been a tough one for integrated energy giants ExxonMobil (XOM 0.02%) and Chevron (CVX 0.44%) due primarily to poor refining results. In addition, falling natural-gas prices have affected ExxonMobil and Chevron's earnings for most of the year, since both companies have made natural-gas production a key strategic priority.

Recently, though, the decline in natural-gas prices has reversed. Due to severe weather conditions across the United States, natural gas recently hit $4.34, representing a six-month high. The abrupt rally in natural gas may now serve to boost earnings for ExxonMobil and Chevron in future periods, which couldn't come at a more opportune time. This is why investors should consider natural gas a potential tailwind heading into 2014.

How Big Oil stands to benefit from a rally in natural gas
While some might assume ExxonMobil to be strictly an oil play, it's also got a huge presence in natural gas. Due to its $41 billion acquisition of XTO Energy in 2009, ExxonMobil is now a leading natural-gas producer. With XTO Energy now under its umbrella, ExxonMobil is the nation's largest holder of natural-gas reserves.

This hasn't worked in ExxonMobil's favor yet, since natural-gas prices have stayed low for most of the year. As a result, ExxonMobil's natural-gas production decreased through the first nine months of 2013 versus the same period last year. However, ExxonMobil is actually reporting higher natural-gas demand. This means that investors can expect ExxonMobil to be quickly incentivized to increase production given the rising price of natural gas.

ExxonMobil's efforts are concentrated in the Piceance Basin, which is a truly impressive region. ExxonMobil holds an interest in approximately 300,000 acres there, and the company's leases hold a potential recoverable resource of more than 45 trillion cubic feet of gas over the life of the project. As a result, it goes without saying that natural gas is incredibly important to ExxonMobil.

Chevron is also committed to natural-gas development, since the company points out to investors that natural gas now comprises 22% of global energy demand. Chevron estimates that as global populations expand, under-developed economies emerge, and the world's thirst for energy grows, natural gas will play an increasing role in the global energy mix.

Chevron produced approximately 5.1 billion cubic feet of natural gas per day in 2012 and will increase production exponentially over the next decade. Specifically, the company points investors to its major projects in Australia and Africa, including the Gorgon Project, which includes a 15 million metric-ton-per-year liquefied- natural-gas facility.

The Foolish takeaway
Aside from their obviously significant oil operations, ExxonMobil and Chevron are making huge investments in natural gas. For most of this year, those efforts haven't paid off, as natural-gas prices languished. Now, that trend is reversing, and natural gas is shaping up to be a strong tailwind for ExxonMobil and Chevron heading into 2014.

It might be difficult to perceive the benefits of natural gas right now, since the headline numbers out of ExxonMobil and Chevron look pretty scary. Indeed, ExxonMobil has posted a 31% drop in net earnings in the first nine months of the year. For its part, Chevron saw a more modest 13% drop in net earnings through the first three quarters of the year.

But as mentioned previously, this is almost entirely due to worsening refining operations. All the while, the fundamentals of natural gas look strong as the new year beckons. Investors interested in the natural-gas industry would be wise not to forget about ExxonMobil and Chevron. Their profits aren't reflecting the benefits of natural-gas production yet, as refining continues to get most of the attention. However, thanks to the rally in natural-gas prices, investors should begin to see tangible benefits from natural gas soon.

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