Many things determine the price of oil, but the most basic force that is currently driving up the price of oil is the fact that demand is expanding relative to supply. This is especially true because countries like China and India are increasing their demand for oil as they expand economically and develop more and more industry. But  beyond this, many things can affect the price of oil. So net consumption has increased. Supply and demand for oil, and thus oil prices could be altered by a host of factors, including a variety of government policies, intentional expansion or reduction of production, natural disasters, new technologies, and other development.