BUZZ-JPMorgan downgrades oil E&Ps as sell-off continues
** JPM downgrades Afren (OW to UW) EnQuest (OW to N), Det Norske (N to UW), Tullow (OW to N) and Ophir (N to UW)
** Collapse of oil price comes at difficult time for sector, bank says, with stretched balance sheets and projects sanctioned with $100/bl in mind
** Afren (LSE: AFR.L - news) , EnQuest (LSE: ENQ.L - news) and Det Norske most heavily exposed to oil price downside
** Tullow to focus more on developments to preserve NAV but means discount set to remain, JPM says
** Sees limited to upside to Ophir with cash bid for Salamander presenting additional risk
** Upgrades Genel from to OW from N, with Kurdistan gas deal seen as transforming co's balance sheet
** Share (Frankfurt: 5CI.F - news) prices highly sensitive to moves in oil Chart: http://link.reuters.com/zas53w (RM (LSE: RM.L - news) : alasdair.pal.thomsonreuters.com@reuters.net)