EOG Resources(EOG 1.19%) stock price is up nearly 200% in the past five years. That rise almost directly correlates to the company's transition from natural gas to oil, and it's just one of the reasons investors are bullish on the stock's future. That being said, no stock is without risk. Here are three things that could take EOG Resources' stock price lower in the future, which just might offer prepared investors a nice buying opportunity.

Leverage to oil works both ways

In 2009, 59% of EOG Resources' production was natural gas. As the following slide shows, the company has dramatically moved away from gas and into oil, so that gas is just 11% of its production.

Source: EOG Resources.

With so much of its production tied to oil, EOG Resources' future is highly tied to the price of oil. That could be a problem in the future since the stocks of oil companies tend to rise and fall with the price of oil -- as the following chart clearly shows.

^XOI Chart

^XOI data by YCharts.

A big drop in oil prices could very likely cause a drop in EOG Resources' stock price. However, given that the world still needs oil, there's just as much likelihood that the price of oil will pick up again in the future. So, any future oil price drop could be a nice buying opportunity for long-term investors in EOG Resources.

Exploration efforts come up dry

EOG Resources' exploration teams have had a great year. The company has uncovered five new oil plays in the U.S. in just the past two quarters. EOG Resources sees four of these five plays delivering after-tax rates of return north of 100%. However, it's still very early in developing these new plays, and there is no certainty that future well results will be as good as the initial results. Disappointments as these plays head toward development could ding the company's stock.

Furthermore, EOG Resources is always on the lookout for its next new play. However, there is no certainty that another new play will emerge anytime soon. While oil companies are getting better at avoiding dry holes, they still do drill them from time to time. A string of dry exploration holes could end up being a big waste of capital and cause the stock to slip. That being said, EOG Resources does have 15 years of oil drilling inventory at its current pace, so time is on its side as it explores for its next oil field.

The law of large numbers begins to hit

Over the past four years, EOG Resources has delivered peer-leading organic crude oil production growth. It expects that to continue at least through 2017. This has helped push it past both Chevron Corporation (CVX 1.75%) and Occidental Petroleum Corporation (OXY 1.19%) as the top oil producer in the lower 48 states, as the following chart notes.

Source: EOG Resources Investor Presentation. 

That chart also notes that both Chevron and Occidental Petroleum have struggled to grow oil production over the past few years. At some point, EOG Resources' production growth will slow down too as the law of large numbers begins to work against the company, which won't be helped by the fact that shale wells have a rapid decline rate that works against its pursuit of growth.

The issue here is the fact that right now, investors are currently willing to pay up for EOG Resources' growth as it fetches twice the enterprise value to EBITDA multiple of Chevron or Occidental Petroleum, as the following chart notes.

EOG EV to EBITDA (TTM) Chart

EOG EV to EBITDA (TTM) data by YCharts.

That won't always be the case. When its growth slows down, investors will begin to assign a lower multiple to the company. This could happen swiftly as a bad quarter, for example, could cause investors to reevaluate how much they are willing to pay for EOG Resources' growth, causing the stock to unexpectedly sell off. Depending on how deep shares sell off, that might actually be a long-term buying opportunity as even with slower growth, EOG Resources still should be able to grow since it has a huge inventory of future drill sites to keep it busy.

Investor takeaway

None of this is to say that EOG Resources' stock will go down. But investors need to realize that the potential is there for the stock to come back a little. When it does, those with a long-term outlook could seize that opportunity and buy the stock.