On May 3, Tallgrass Energy Partners said it had identified 42 potential acquisitions or new projects totaling more than $6.1 billion in investment that could fuel its growth.

Two of the potential projects are valued at around $1.5 billion each. One would be a greenfield or wholly new project, while the other would require building out or redeveloping existing assets, executives said.

Most of the projects fall in the same categories and are focused on natural gas or oil, the executives said on a conference call on May 3, noting "there's no corporate M&A" on the list.

Midstream companies such as Tallgrass were hurt by low oil prices during the last three years as volumes on their pipelines fell and opportunities for growth dwindled.

But a deal by major oil producers in November 2016 to cut production and stabilize global oil prices has given a boost to U.S. crude prices and prompted midstream companies to explore new infrastructure projects.

"In the next 90 to 100 days, if we don't have a couple hundred million dollars of acquisitions or projects ... we will be very disappointed," said Tallgrass CEO David Dehaemers.

On May 3, rival Magellan Midstream Partners said it was evaluating a new pipeline to transport crude and condensate from the Permian Basin to Corpus Christi, Texas.

Tallgrass Energy's 320,000 barrel per day (Mbbl/d) Pony Express, which transports crude from Guernsey, Wyo., to the massive oil storage hub in Cushing, Okla., averaged 262 Mbbl/d of throughput in the first quarter of this year, executives said.

The pipeline averaged just 242 Mbbl/d in January, due in part to production halts from cold weather and increases in drilled but uncompleted wells, while March volumes jumped to 277 Mbbl/d, the company said.

The company currently is building a more than 100 Mbbl/d connection between that Pony Express line and HollyFrontier Corp.'s El Dorado refinery. That project is still on schedule for completion by the fourth quarter of 2017.