Mandelbrot and oil price volatility.A tad too statistical, but essentially Mandelbrot proved that prices of commodities do not follow a normal distribution (Gaussian), but are rather erratic with volatility from 'mild' to 'wild'. We are now in a 'wild' volatility period meaning that a drop/increase in price more than 3 sigma (standard deviations) away from the mean is more likely than ever to be followed by another one.
So $20 Brent is not beyond the pale.
Let's hope for our sake that level is reached soon and catharsis happens fast.
https://www.reuters.com/article/oil-prices-kemp-idUSL5N11828J20150902