What do 'rig' and 'shale bed' here mean ?
1. What does 'rig' mean ?

However, the output of the shale firms has proved surprisingly robust, even though they have cut their number of rigs significantly since the peak last October (see chart).

Another sentence:- "Its main influence used to be OPEC, and particularly the Saudis, switching the taps on and off to try to rig the price".

2. Does 'shale beds' mean 'shale formations' (in the earth) ?

As American production continues to rise, pressure will grow on the government to ease its restrictions on exports of crude. In the meantime America’s imports are diving—they fell below those of China last month. Other countries, from Russia to Argentina, have promising shale beds.

Thanks

http://www.economist.com/news/business/21651267-american-shale-firms-are-now-oil-markets-swing-producers-after-opec

Question

What do 'rig' and 'shale bed' here mean ?
1. What does 'rig' mean ?

However, the output of the shale firms has proved surprisingly robust, even though they have cut their number of rigs significantly since the peak last October (see chart).

Another sentence:- "Its main influence used to be OPEC, and particularly the Saudis, switching the taps on and off to try to rig the price".

2. Does 'shale beds' mean 'shale formations' (in the earth) ?

As American production continues to rise, pressure will grow on the government to ease its restrictions on exports of crude. In the meantime America’s imports are diving—they fell below those of China last month. Other countries, from Russia to Argentina, have promising shale beds.

Thanks

http://www.economist.com/news/business/21651267-american-shale-firms-are-now-oil-markets-swing-producers-after-opec

Answer

Rig can have more than one meaning.

In the first sentence it is referring to 'oil rigs', which are the facilities used to drill, extract and process crude oil.

The verb 'to rig' means to 'to fix' or 'to tamper' i.e. they are trying to manipulate the situation so that the oil prices are favourable for them.

Yes shale beds refers to the shale formations in the Earth, from which they will get the oil.

Answer

"To rig" as used here means to manipulate or control, for example you might call an election rigged if the votes were manipulated.

And yes, "shale beds"  would be the layers of shale in the earth. It's saying that they seem like they will have plenty of oil.