ExxonMobil (XOM 0.28%) and Occidental Petroleum (OXY -0.56%) are among the top-performing oil stocks of 2022 so far. It's not surprising to see why: Crude oil prices shot up to 15-year highs this year, raking in copious amounts of money for oil exploration and production companies. Both ExxonMobil and Occidental Petroleum have cashed in on high oil prices this year and aggressively pared debt, invested in growth, and boosted their dividend payouts.

Yet, if you were to pick only one oil stock right now, which one should it be and why? Here's the bull case for ExxonMobil and Occidental Petroleum stocks to help you decide.

ExxonMobil stands out for its financial fortitude and plans

Neha Chamaria (ExxonMobil): ExxonMobil is one of the largest oil and gas companies in the world, but that's not why you should consider the stock. Exxon is also one of the world's largest integrated oil and gas companies. To be sure, Occidental is an integrated oil company as well, but it still derived almost three-quarters of its sales last year from upstream operations. While that might make Occidental stock more alluring in a rising oil-price environment, a more diversified oil stock should help you ride out the long-term volatility in oil and gas better.

More importantly, Exxon's financial standing right now is as solid as it can get. Exxon held only around $39.5  billion in long-term debt as of June 30. To put that into perspective, the oil giant earned $23 billion in net income and generated nearly $35 billion in cash from operations in just the first half of 2022.

The best part is that Exxon's ongoing efforts to cut costs should help it earn strong margins even if oil prices fall further. Exxon's global cost of production allowed it to break even at a crude oil price of only $41 per barrel last year. If things go as planned, its break-even oil price could come down to only around $30 per barrel by 2027. By then, Exxon could accumulate billions of dollars in incremental cash flows, a good portion of which will likely end up in shareholders' pockets as bigger dividends. Exxon is already one of the top dividend-paying oil stocks with an unbeatable 39-year streak of consecutive annual dividend increases.

Occidental Petroleum is benefiting from the Warren Buffett effect

Matt DiLallo (Occidental Petroleum): While the fortunes of ExxonMobil and Occidental Petroleum rise and fall with oil prices, Occidental has one additional catalyst that gives it the edge over Exxon in my book. That's the fact that Warren Buffett's company, Berkshire Hathaway (BRK.A 0.61%) (BRK.B 0.79%), has been gobbling up shares of Occidental and Exxon's chief rival Chevron but hasn't purchased one share of Exxon.

Berkshire currently owns 188.5 million shares of Occidental Petroleum, which is 20.2% of its updating stock. That stake is worth about $12 billion. In addition, Berkshire has stock warrants to buy another $5 billion in Occidental shares and a $10 billion preferred-stock investment. Furthermore, Buffett has received regulatory approval to buy up to 50% of the oil company's outstanding shares. Berkshire has also built up a more-than $25 billion stake in Chevron.

Many have speculated Buffett might eventually make an offer to acquire Occidental since his purchases seem to follow a similar pattern to his investment in railway giant BNSF in 2010. Berkshire accumulated a more-than 20% stake in that company before buying the entire business.

That possibility of a Berkshire buyout should put a floor under Occidental Petroleum's stock price if oil prices continue cooling off. Likewise, Chevron's stock should hold up relatively well if crude keeps slumping since Berkshire will likely buy more shares. However, Exxon doesn't have the benefit of a Buffett floor. That gives it more downside risk, while Occidental has the potential for more upside if Buffett does make a bid in the future since he would likely need to pay a premium to acquire the remaining shares.

While I think Exxon is a solid oil company, Buffett's investment skews the risk-reward in Occidental's favor, making it a better buy between the two.

The better oil stock

Occidental Petroleum and ExxonMobil are both solid oil stocks, having cut debt drastically in recent quarters to reward their shareholders even more richly. Yet, Occidental Petroleum shares have already doubled this year and more than doubled Exxon's returns, thanks to Buffett. So even though Occidental stock could continue to ride the Buffett wave in the near future, ExxonMobil might appeal more to the cautious investor looking to bet on oil prices for the long term.