Seaport Global Securities released its top 10 oil and gas pick list on Tuesday with a few additions, including Synergy Resources (SYRG) at the top of the heap.

The other names on the list -- in order of their ranking -- include Newfield Exploration (NFX) , Energen (EGN) , Ring Energy (REI) - Get Report , Parsley Energy (PE) - Get Report , Continental Resources (CLR) - Get Report , Noble Energy (NBL) - Get Report , Eclipse Resources (ECR) - Get Report , Cimarex Energy (XEC) - Get Report and RSP Perman (RSPP) .

The report, authored by senior analyst Mike Kelly and others, said underlying economics at Synergy as well as newcomer Noble Energy continue to improve with operational gains and that valuations are currently quite appealing, especially on Synergy given its growth profile.

The investment bank thinks Synergy could expand its production by 81% next year, 30% higher than consensus. It blames the stock's recent underperformance on its acquisition of $505 million worth of properties in Colorado from Noble, saying it presents a "compelling" entry point. The analysts said its "immaculate balance sheet" and improved inventory after the Noble purchase provides ample running room. They kept their price target for the stock at $8.50 (it closed at $6.20 yesterday).

As for Noble, the analysts expect the company to achieve strong growth and say it has a cheap valuation relative to its peers. They added that the company's meaningful capital efficiency improvements in the Denver-Julesburg Basin in Colorado take its internal rate of return to more than 80% at $50 per barrel oil. They also note that Noble has valuable exposure to West Texas' southern Delaware Basin with recent wells beating type-curve by more than 50%. The bank bumped up its price target on the stock to $45 from $36 (it closed yesterday at $35.95).

Seaport said four of its six upgrades this quarter -- including Eclipse and Noble, along with Carrizo Oil (CRZO) - Get Report and WPX Energy (WPX) - Get Report -- are in line with a "positive rate of change" trade in which relative outperformance can come from either higher commodity prices or improving capital efficiency. "We're still willing to overlook higher leverage as long as the operational trajectory is notably improving," the analysts said.

The investment bank upgraded Synergy, Eclipse and Noble to buy ratings while it moved Carrizo and Concho Resources (CXO) - Get Report from neutral to accumulate and WPX from sell to neutral.