As the world's third-richest person and most celebrated investor, Warren Buffett attracts a lot of attention. Thousands try to glean what they can from his thinking processes and track his investments.

We can't know for sure whether Buffett is about to buy ExxonMobil (NYSE: XOM) -- he hasn't specifically mentioned anything about it to me -- but we can discover whether it's the sort of stock that might interest him. Answering that question could also reveal whether it's a stock that should interest us. In this series, we do just that.

Writing in a recent 10-K, Buffett lays out the qualities he looks for in an investment. In addition to adequate size, proven management, and a reasonable valuation, he demands:

  1. Consistent earnings power.
  2. Good returns on equity with limited or no debt.
  3. Management in place.
  4. Simple, non-techno-mumbo-jumbo businesses.

Does ExxonMobil meet Buffett's standards?

1. Earnings power
Buffett is famous for betting on a sure thing. For that reason, he likes to see companies with demonstrated earnings stability.

Let's examine ExxonMobil's earnings and free cash flow history:

Source: S&P Capital IQ.

Over the past several years, ExxonMobil's earnings and free cash flow have fluctuated somewhat with the price of oil, but they've rebounded and the company has managed to remain profitable throughout.

2. Return on equity and debt
Return on equity is a great metric for measuring both management's effectiveness and the strength of a company's competitive advantage or disadvantage -- a classic Buffett consideration. When considering return on equity, it's important to make sure a company doesn't have an enormous debt burden, because that will skew your calculations and make the company look much more efficient than it is.

Since competitive strength is a comparison between peers, and various industries have different levels of profitability and require different levels of debt, it helps to use an industry context.

ExxonMobil generates a high return on equity -- 27% over the past year, 28% on average over the past five years -- while employing a modest debt-to-equity ratio of 11%.

3. Management
CEO Rex Tillerson has been at the job since 2006. He's been at Exxon in various other jobs as far back as 1975.

4. Business
Oil and gas exploration and production can obviously be subject to swings in energy prices and a recent spurt of innovation, but so far at least, it's not an industry that's been particularly subject to technological disruption.

The Foolish conclusion
So is ExxonMobil a Buffett stock? It could very well be. The company exhibits several of the quintessential characteristics of a Buffett investment: consistent earnings, high returns on equity with limited, tenured management, and a straightforward business. If you're looking for some other promising energy stocks, I also suggest you check out "3 Stocks for $100 Oil," a special report from the Motley Fool. I invite you to grab a free copy to discover everything you need to know about these three names.