They are currently in a price war with the U.S. oil industry. Prices may be low now but they are sure to go up after OPEC is through. They are hoping that as prices continue to fall the US oil producers will just give up because they view it as unprofitable.
The cost of oil has plummeted recently thanks to OPEC. This might be bad for the oil industry in North America because it counteracts their argument for the need to do harmful acts like fracking and the Keystone Pipeline, but it's good if it stops those things. Ultimately, oil is not sustainable at any cost.
OPEC has the ability to inflict harm on North America's oil industry. And I wouldn't be surprised if it happened because they simply don't care. Business is mostly a heartless industry to be in, and most people in it won't do anything to prevent injury to another person, especially in the pocket.
OPEC is trying to muscle North America out of oil production. They are lowering rates per barrel by keeping production high to price new producers out of the market. It would be nice to see the government provide subsidies to American producers to keep this from happening and lessen or dependence on foreign oil.