With little fanfare, Bakken Shale-focused oil producer Oasis Petroleum (NYSE: OAS) completed an initial public offering (IPO) of its midstream arm, Oasis Midstream Partners (NYSE: OMP), last September. The deal provided Oasis Petroleum with some cash to fund its expansion efforts while giving income-seeking investors a new high-growth, high-yielding option for their portfolio.But while Oasis Midstream boasts some eye-catching numbers, income-seekers might want to consider putting this new master limited partnership (MLP) on their watch lists for the time being.