The reality is that the Saudis despite falling prices are producing whatever amount of oil that is necessary to maintain their income. They have huge ongoing cash requirements as they are subsidizing Egypt and other Sunni clients. Without the Saudi aid, the price of food and other essentials would skyrocket. There would be hunger and political chaos in Egypt. This situation underscores just how precarious “stability” is in the region. The Saudis know that if Egypt devolves, the terror of the “Arab Spring” will sweep them as well.
Most analyst consensus is Saudi is operating at a loss, compared to their spending, not the cost of producing oil.
But they also started into this price drop with nearly $800 billion in cash reserves. I don't think Russia or the other OPEC nations are near that point, relative to their spending.
Saudi oil production is actual down from last year at this time.