On May 16, 2016, we have issued an updated research report on ONEOK Partners L.P. OKS, a master limited partnership ("MLP") engaged in gathering, processing, storage and transportation of natural gas in the U.S. Ongoing investments in growth projects and conversion to fee-based contracts will likely drive its performance in the future. However, stringent regulations, along with volatile commodity prices,are potential headwinds.During the first quarter of 2016, ONEOK Partners’ earnings surpassed the Zacks Consensus Estimate and surged year over year driven by fee-based earnings growth. Revenues, on the other hand, missed estimates and were down from the year-ago quarter primarily due to lower commodity sales.ONEOK Partners continues to expand its scale of operations through organic projects primarily in the mineral-rich areas of Williston Basin and Permian Basin among others. The partnership projects capital expenditure of $600 million for 2016. Continued investment in growth projects will allow it to serve more upstream players, thereby ensuring higher distribution for ONEOK Inc. OKE.Moreover, ONEOK Partners strives to maintain a stable cash generating capacity through operating activities. During the first quarter, the partnership’s cash flow from operating activities was $266.3 million, up substantially from $65.1 million in the year-ago period. A stable cash inflow enables the partnership to pursue multiple growth ventures.The partnership has also been pursuing strategies to convert percent-of-proceeds-based contracts to fee-based contracts to reduce commodity price exposure and boost margins. Contract restructuring in the Natural Gas Gathering and Processing segment has significantly reduced the segment's commodity price sensitivity, thereby making significant contributions to the partnership's first-quarter results. Further, the partnership expects the segment's earnings to increase to more than 75% fee-based this year, driven by contract restructuring efforts.On the flip side, dependence on the upstream players’ activities remains a major concern for the partnership. If upstream players reduce their exploration and production activities to counter unfavorable price movements, ONEOK Partners’ midstream services will be affected. This will subsequently hurt the partnership’s cash inflow.Zacks Rank & Key PicksONEOK Partners currently carries a Zacks Rank #3 (Hold).A couple of top-ranked peers in the same space include PBF Logistics LP PBFX and Rose Rock Midstream, L.P. RRMS, both carrying a Zacks Rank #1 (Strong Buy).Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report ONEOK INC (OKE): Free Stock Analysis Report ONEOK PARTNERS (OKS): Free Stock Analysis Report PBF LOGISTICS (PBFX): Free Stock Analysis Report ROSE ROCK MIDST (RRMS): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research