Oasis Midstream Partners LP, an MLP formed by Oasis Petroleum to own midstream assets in the Williston Basin, raised $128 million by offering 7.5 million units at $17, below the range of $19 to $21. Oasis Midstream Partners LP plans to list on the NYSE under the symbol OMP. Morgan Stanley, Citi, Wells Fargo Securities, Credit Suisse, Deutsche Bank, Goldman Sachs, J.P. Morgan and RBC Capital Markets acted as lead managers on the deal.