Source: Chevron, Facebook.

What: Shares of global integrated oil and gas giant Chevron (CVX 0.75%) rose fractionally by $0.10 to close at $107.96 in Tuesday's trading session despite receiving a rating downgrade from research company Oppenheimer.

So what: According to Fadel Gheit and Luis Amadeo, the analysts at Oppenheimer who reduced Chevron's rating from an "outperform" to "market perform" and removed its previous $115 price target, Chevron is considerably pricier than its large integrated oil and gas peers and it's obviously exposed in its drilling operations to weaker crude oil prices.

Based on estimates provided by Oppenheimer, Chevron is expected to generate $34.8 billion in EBITDA in 2015 and $42.2 billion in 2016 as oil prices begin to stabilize. Taking into account a capital expenditure budget of $31 billion and an annual dividend payment that totals around $8 billion, Oppenheimer projects a free cash flow shortfall in the neighborhood of $8.3 billion in 2015 and $3 billion in 2016. Oppenheimer also cited a lack of share buybacks since they were suspended when oil prices fell.

Now what: Taking in Oppenheimer's concerns, the question investors have to ask here is whether or not this downgrade serves as a warning to keep your distance from Chevron, or if Wall Street is merely being overly cautious with the energy giant.

A case could certainly be made for both sides.

Source: Chevron, Facebook.

On one hand, even though Chevron operates a diversified business model where weakness can be hedged by its refining and midstream operations, it's still reliant on its upstream segment for the bulk of its revenue. This implies that a contraction of its top and bottom lines is inevitable, and that until a floor is put in place for Brent and WTI crude, its share price could suffer. The lack of a regular share buyback may also be negatively felt by investors.

But Chevron's global diversity is also a calling card to its success. Its roughly two dozen natural gas discoveries off the coast of Australia, which will add 10 trillion cubic feet of resources to Chevron's already impressive reserves, place it in prime position to benefit from China's and Southeast Asia's industrialization over the coming decade. This is but one example of Chevron's numerous global growth-driving assets. 

So, to answer the above question of whether this downgrade could represent an overreaction or a genuine warning, I believe it really depends on your time horizon. It's very reasonable to expect Chevron shares to be volatile and maybe even weak over the next few months, or perhaps a bit longer. Chevron may be diversified, but like any driller, it needs higher prices to drive its margins.

However, if your investment horizon is a few years or longer, then I don't see any reason you can't consider Chevron shares as a potential buy, here. With a 3.8% dividend yield, you can get paid to wait patiently for a turnaround in a company that has historically done very well by its shareholders.