It's all down to panic by the buyers. Production is at it's highest level for years so prices should be low. However, the oil companies are stock piling so they can still sell at high prices if it all goes pear shaped.
Interestingly, when the price of oil drops the cost of petrol will remain high as they have paid for the stockpiled oil and need to recover that cost. Funny how the cost of petrol seemed to go up immediately the scare started and didn't wait for the cheap oil, that was already in the purchasing system, to run out.!!