Population matters (31M vs 5M-9M). Besides Nordics have much freer markets and they do not confiscate private property like this.
One of the big impact of the cost of Venezuelan crude is its high content of sulfur, which makes refining more expensive, but to this day, Venezuela is one of the few countries where even with a low barrel price, the activity is profitable, or at least it should be.
But when you have a state company that has quadrupled its payroll, paying for all kinds of social services in the country, corruption, all while also diverting funds from investment, you make the operation run at a loss.