** Citigroup raises price targets on U.S. energy companies, citing a gap between exploration and production (E&P) stock valuations and oil prices

** Brokerage says investors should focus on companies that remain attractive even if crude prices fall

** Citi upgrades Ovintiv OVV.N rating to "buy" from "neutral" citing strong operations, a stronger balance sheet and potential inflows after a peer deal

** Brokerage also upgrades California Resources Corp CRC.N, citing better margins, a more stable production outlook and rising investor interest