I think it's mostly the uncertainty regarding the situation in Iran and the very clear decision of the IAEA to refer the country to the UN Security Council.
The situation between Russia and Ukraine is a rather (supportive) factor for oil ... as the potential for (gas) supply disruption in Europe is having a correlating effect on other energy commodities including oil.
The situation in Nigeria is likely to remain volatile for some time. Prices should rise because of disruptions in supply.
The reason for the rise is the increase in the geo-political risk premium because of the situation in Iran.
The Iranian situation is increasing the geopolitical risk premium that the market builds into the price of oil.