NEW YORK (TheStreet) -- Oil prices are sliding again, and I'm being asked how low oil prices can go.

The most pessimistic prediction has come from Citibank, which has said crude oil could fall as low as $20 a barrel this year, but prospects for $20 oil are as unlikely as the predictions for $60 oil were only a few weeks ago when it looked like an imminent and sustained recovery was just over the horizon.

Fundamentally, there is little to stop oil's slide right now. An interim January low of $43 was broken on Wednesday, and the chart analysts are finding it difficult to predict a bottom.

Oil stockpiles are still increasing, with 458 million barrels in storage, by far a new record. At the rate of increases in stockpiles, it is estimated that storage will be completely used up by the middle of May. With virtually nowhere to put oil, prices will again have nowhere to go but down.

And that would be catastrophic, not just for the oil industry, but for the U.S. economy. So far, tens of thousands of jobs have been lost in the oil and gas sector because of falling prices. But a crude oil price of less than $30 would bankrupt dozens of oil companies much more quickly and cause the loss of several hundred thousand jobs. And most of these jobs are high-paying middle-class jobs that support families and have been a strong addition to our economy.

Is there anything that can stop the slide of oil prices? Two possible exits are still available for oil that is reaching its limit in storage.

One is an increase of exports, either through a one-time dispensation by the U.S. government that circumvents the crude oil export ban. This would be unprecedented but made possible by the real limits of storage that might be reached. In addition, several oil companies could try to circumvent the export ban by "self designating" processed oil as condensate, as BHP Billiton (BHP) - Get Report has recently done.

A second is the abandonment of forward contracts for imported oil that some end users have. Even with the possibility of lawsuits and fines, the savings for buying $25 or $30 barrels on the cash market would be worth it. This would be equally unprecedented, but with cash oil dropping to such a low level, it would become possible.

I talk more about the likelihood and repercussions of oil prices in the $20 range with Brittany Umar in the video above.

This article is commentary by an independent contributor. At the time of publication, the author held TK positions in the stocks mentioned.