If the given image is of any indication brent crude oil might bottom out at 75-80 range as many of the major crude oil producing countries will fall into chaos and will try everything to support crude prices.
If oil prices bottom out in this range many of the Indian and international producers such as Cairn India, ONGC, BP, Conco Phillips will provide good stock price appreciation from current levels in medium to long term.
Globally, the weaker oil price means more money in the hands of consumers. World oil exports averaged about 40m barrels a day last year; a $30 drop in the oil price, which is roughly the fall in the Brent benchmark since June, would transfer more than $400bn from oil exporters to consumers if oil prices stay at current levels for a year. This is very good news for FMCG, Autos, Airlines and many other industries that depend on oil and it's by products .
One country to watch out very closely is Venezuela as it needs roughly $160 a barrel to balance it's budget. At half of that price it might be forced to default on it's debt repayment. This event could trigger short term panic in equity markets for the fear of cascading effect on other vulnerable countries.