Plains All American Pipelines (PAA 0.62%) is coming off a great year. The oil pipeline master limited partnership (MLP) delivered guidance-crushing results during the fourth quarter, enabling it to exceed its full-year outlook. On top of that, the company made excellent progress on its strategic plan to reduce debt, which allowed it to increase its distribution by 20% in 2019.

While it will be tough for the MLP to repeat that performance this year, investors hope that it can continue producing strong results. They'll get their first glimpse at Plains All American's progress so far when it reports its first-quarter numbers later this week. Here are the two most important things to watch in that release.

Red pipelines at an oil storage terminal.

Image source: Getty Images.

1. See if results matched guidance

Plains All American Pipelines put out its guidance for 2019 when it reported fourth-quarter results in early February. At the time, the company thought it would generate about $2.75 billion in adjusted EBITDA, which implies about 2.5% growth compared to last year. That's a much slower growth rate due to an asset sale, and the anticipation that its commodity-price-driven supply and logistics business won't contribute quite as much as it did last year.

The MLP expects to haul in 27% of its total earnings during the first quarter, implying that it should generate roughly $742.5 million in adjusted EBITDA during the period. That would, however, be up sharply from the $593 million it produced in the year-ago period due to the impact of recently completed expansion projects. Ideally, Plains All American will stay on track with that forecast. One area to watch, however, is supply and logistics earnings, which could come in stronger than expected due to the rebound in oil prices so far this year.

A close-up of a pipeline under construction.

Image source: Getty Images.

2. Keep an eye on capital projects

After spending $1.9 billion on growth projects last year, Plains All American only anticipates investing $1.1 billion in expansions in 2019. However, that's up sharply from its initial view that it would only spend $650 million this year because it recently approved several projects, including a large-scale oil pipeline joint venture with ExxonMobil (XOM -0.95%) and Lotus Midstream.

Investors should see if the company makes any more changes to its capital spending plans for 2019. One area to watch is that pipeline with ExxonMobil. That's because rival Energy Transfer (ET 0.62%) and its partners canceled their competing oil pipeline project earlier this year due to that company's desire to combine them into one higher-returning investment. That could result in Energy Transfer joining Plains All American on the ExxonMobil pipeline, which might cause the original partners to invest less capital in the project.

On the other hand, the company could also sanction additional expansions. Plains All American has several projects in development, including expanding its Red River and Diamond Pipelines as well as reversing the flow of oil on the Capline system. Those projects would fuel growth in 2020 and beyond, which makes them worth watching.

In addition to that, the improvement in oil prices this year could drive drillers to increase their activity levels. That could fuel the need for smaller-scale expansions like more oil gathering pipelines and related infrastructure in places like the Permian Basin, where Plains All American has been rapidly expanding its midstream footprint.

Hoping that the momentum will continue

Plains All American Pipeline expects to continue growing this year even though it will face some headwinds from a large-scale asset sale and a tough comparable at its volatile supply and logistics segment. A strong first-quarter showing, however, could set the stage for the oil pipeline company to outpace its muted expectations for 2019. Meanwhile, success in securing more capital projects could enable Plains All American to grow at an accelerated pace in the coming years. That would give the MLP more fuel to reward investors through additional distribution increases.