(Reuters) -Oil & gas pipeline operator Crestwood Equity will be bought by Partners LP. Oasis Petroleum (NASDAQ) Inc’s midstream unit was acquired by a deal worth $1.8 billion to grow its footprint in the U.S. shale basins.

This cash-and stock deal is made at a time when oil and gas prices are reaching multiyear highs. It boosts shareholders’ confidence and encourages mergers.

Crestwood stated that the “commodity price outlook remains favorable for an acceleration of activity across the basin”, referring to North Dakota’s Williston Basin.

Altus Midstream Co. announced last week that it was merging with BCP Raptor. This holding company owns pipeline assets located in the Permian basin. The combined entity will be worth $9 billion inclusive of debt.

Crestwood projects it will capture more than $20 million annually in additional cash flow from Oasis over the next few years. It also identified approximately $25 million annual cost savings soon after closing the Oasis transaction in 2022.

Crestwood stated on Tuesday that it plans to raise its distribution to $2.62/unit annually. This is a 5% increase over the previous year.

Oasis Petroleum receives $150 million cash, an average of 21 million units and $150 million in cash in return for the 33.8 million units it holds in its midstream business. Oasis Midstream will pay it $10 million for the General Partner Interest.

Oasis Middlestream sharesholders, who owed $660 million in outstanding debt as of Sept. 30, 2017, will be eligible to receive 12.9 million Crestwood units and 14.8 million shares.

The combined company’s enterprise value will amount to approximately $7 billion.

Oasis Middlestream Unitholders will control approximately 35% Crestwood’s units. Oasis Petrol will take 22%.