The United States current export restrictions were adopted during the 1970s, a period of extreme price controls.
By 1981 the price controls on crude oil had been eliminated, but export restrictions persisted.

On December 18, 2015, The U.S. Congress voted to repeal a 40-year ban on oil exports, allowing producers to sell crude oil overseas.

The application of horizontal drilling and multistage hydraulic fracturing has catalyzed a renaissance in oil production.
After decades of decline, crude oil production in the United States has recently been increasing rapidly.

Crude oil and petroleum products are global commodities and their prices are determined by supply and demand factors on a worldwide basis.
Why has the price of oil been dropping so fast and why now?
Supply and demand along with US oil export are main drivers that put pressure on oil for near time delivery, i.e. contango market.
Brent forward curve has deepened its contango as crude oil oversupply continued in all regions.

Currently, OPEC members keep actual production levels steady.
The cartel uses a wait and watch approach. The chart below represents estimates for crude oil OPEC production.

Non-OPEC producers, including Russia, continue to increase its oil production.

All these facts leads to a simple conclusion that the oil market will remain oversupplied in 2016. What about the price?
It seems like the average price will be around $35 per barrel in 2016.

Today, market participants are focusing on U.S. oil production, whose relentless growth in recent years fueled the global oversupply.
Also, an increase in Iranian output following the removal of the international sanctions will put additional pressure on oil prices.

A central factor in the sharp price drops is the continuing unwillingness of OPEC to stabilize the oil market.
Without dramatic production cuts by OPEC, it’ will probably take until the end of 2016 for the market to see a rebalance of supply and demand.