Brent's failure to sustain above $48.34 (50% of May 2015 high-Jan 2016 low), especially if preceded by a rejection at rising trend line (red) would open doors for a slide to $46.90 (rising trend line - blue).
On the higher side, only a day end closing above falling trend line resistance would signal oil has made a short-term bottom and thus could yield a rise to $51.00 levels aain.