The price of oil has jumped around quite a bit this year. After plunging at the end of last year, the U.S. oil benchmark price, West Texas Intermediate, rallied above $65 a barrel at one point, before tumbling back into the mid-$50s.

While oil is still up sharply on the year, all that volatility has had a direct impact on the cash flows of oil producers. However, it hasn't had much effect on pipeline companies, since they get paid steady fees as volumes flow through their system no matter the price of crude. They are therefore a much lower-risk way to invest in the oil market. While several are compelling buys right now, Enbridge (NYSE:ENB), Enterprise Products Partners (NYSE:EPD), and Phillips 66 Partners (NYSE:PSXP) all have near-term catalysts. That makes them the best ones to buy this December. 

A pipeline and an oil pump at sunset.

Image source: Getty Images.

A big boost is right around the corner

Enbridge operates the longest and most complex oil pipeline system in the world. The Canadian company transports 25% of all the oil produced in North America, including 62% of U.S.-bound Canadian exports. It gets paid steady fees as that crude flows through its systems, which gives it the cash to expand its operations as well as pay an attractive 5.8%-yielding dividend.

The company recently completed the largest expansion project in its history, replacing its Line 3 oil pipeline system in Canada. It's one of $9 billion worth of expansions, in Canadian dollars, (that's about US$6.8 billion) that it expects to finish this year. Those growth projects should supply the company with enough cash flow to grow its dividend by another 10% next year. Meanwhile, it has plenty more growth coming down the pipeline, which should supply it with the fuel to increase its dividend by 5% to 7% per year after 2020. With its recent project completions providing a near-term boost, Enbridge is an excellent oil stock to buy this December.

A well-oiled dividend growth machine

Enterprise Products Partners also recently put the finishing touches on a major oil pipeline expansion, as it started up its Midland-to-ECHO 2 project earlier this year. That's one of $5.5 billion of projects the energy master limited partnerships (MLP) expects to complete by the end of 2019. Those expansions will give Enterprise the fuel to continue growing its distribution to investors, which currently yields 6.8%.

The MLP has increased that payout for the last 22 years, including raising it for the past 61 consecutive quarters. That trend should continue for at least the next several years since Enterprise has $9.1 billion of expansion projects set to come online through 2023. Add that visible growth to its top-tier balance sheet, and this oil stock should continue to richly reward its investors in the coming years, making it a great buy this month.

A close up of a pipeline under construction.

Image source: Getty Images.

About to hit the accelerator

Phillips 66 Partners is also starting up a new major oil pipeline project. Its Gray Oak system, which counts Enbridge as a partner, began its initial service in November. The $2.7 billion project will supply the MLP with a big dose of cash flow in the coming quarters as volumes start flowing through the system.

That will give Phillips 66 Partners the funds to continue increasing its 6.2%-yielding distribution to investors. The MLP has already grown it in each of the past 24 consecutive quarters, including raising it 9% in the past year. That trend should continue through at least 2021, since Phillips 66 Partners has four more expansions after Gray Oak that are on track to come online over the next 18 months. Meanwhile, with a top-notch financial profile, it has plenty of financial flexibility to continue growing its midstream footprint as well as its investor payout.

Low-risk ways to invest in the oil market

Oil price volatility turns off a lot of investors from buying oil stocks. However, most pipeline companies don't have much direct exposure to prices, which makes them lower-risk ways to invest in the sector. Enbridge, Enterprise Products Partners, and Phillips 66 Partners stand out these days, since each one has near-term catalysts that should give them the fuel to generate high-octane total returns in the coming months. That makes them great oil-related stocks to consider buying this December.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.