Crestwood Equity Partners (NYSE:CEQP) was by far the best-performing master limited partnership (MLP) last year. That success has continued in 2019, in part because of an improving oil market and the company's high-end fourth-quarter results. Overall, the MLP has generated a nearly 60% total return since the start of last year after adding in its high-yielding distribution.

Investors will get their next data point on Tuesday, when Crestwood reports its first-quarter numbers. A strong showing could give the MLP the fuel to continue outperforming. Here's what would need to be in that report for this to happen.

A hand drawing three lines, with one rising above the others.

Image source: Getty Images.

A clear acceleration in its financial results

Crestwood Equity Partners' turnaround plan started paying dividends late last year. After declining for several years, earnings and cash flow finally reversed course and began improving, thanks to the company's expansion program. That trend should become even more apparent during the first quarter as volumes rise on those newly expanded systems.

The first quarter, however, should only be the beginning. The company recently bought out Williams Companies' (NYSE:WMB) 50% stake in their joint venture in the Powder River Basin. That deal, which closed earlier this month, will immediately boost Crestwood's cash flow as well as its growth prospects. As a result, the company now sees cash flow coming in between $275 million and $305 million. That's a meaningful bump from its initial forecast range of $245 million to $275 million.

On top of that acquisition-fueled boost, Crestwood anticipates an acceleration in volumes during the second half as additional projects come online. For example, the company expects to finish its Bear Den 2 and Bucking Horse natural gas processing plant expansions in the Bakken and Powder River Basin, respectively. On top of that, it will see a 10% step up in cash flow from its Stagecoach joint venture with Consolidated Edison (NYSE:ED) beginning in July.

Notable progress on adding more expansion projects

The acquisition of Williams' stake in their Powder River joint venture will shift that project's expansion-related spending to Crestwood. As a result, it now expects to invest between $425 million and $475 million on expansion projects this year. That's up from its initial view of $275 million to $325 million in growth-related spending this year and a significant jump from last year's level of $332 million. That increased investment positions the company to grow cash flow at a more than 20% rate over the next two years.

While 2019 will be a heavy investment year for Crestwood, 2020 looks light, since the company currently only has $100 million to $150 million of expansion-related spending on the docket. As a result, the company's growth engine could slow down after next year -- unless the company secures additional expansions. It currently has several opportunities under development, including building a second Orla gas processing plant to support customers in the Delaware Basin as well as expanding its services in that region to include crude oil gathering and water handling. Meanwhile, the company and Consolidated Edison could potentially expand their Stagecoach joint venture to capture growing natural gas volumes in the Marcellus Shale. Crestwood's ability to continue securing high-return expansion projects would help it maintain fast-paced earnings growth beyond next year.

Anticipating a strong quarter

Crestwood Equity Partners' turnaround efforts have been paying off over the last year. The company's cash flow recently started its upward turn, which should continue in the first quarter. That acceleration, along with the potential addition of new growth projects, could give the MLP the fuel needed to continue outperforming.