According to the Business Standard Venezuela will start the Petro after the Presidential Election May 20th.
16 Crypto-Exchanges have been licensed to handle it:
Cripto Exchange, Cripto Capital, Asesoría Financiera C.A., Italcambio, Ambere Coin, Cake Blockchain, Valorata Casa de Cambio, Coinserve, Cripto Lago, Cripto Venezuela Traing, Cripto Monex, Bancor, Cripto Mundo Casa de Intercambio C.A., Inversiones Financieras 1444 C.A., and Cripto Activo Ex.
Also Indias Coinsecure aparently was offered a license in order to trade it against BTC and Rupees there. The venezuelan government offered a 30% rebate if India paid for oil with Petros.
The cash-strapped nation, facing high inflation due to US sanctions, is planning to make Petro its official currency by 2020. (Business Standard)
Not sure how a limited supply of a 100 million Petros will allow for being all the currency that exists in Venezuela for 2020. I suppose that here once again comes the fractional reserve banking into play, so that with 5 billion base money and a 1% reserve banks can create another 495 billion USD worth in Petros.
We will see what happens in the next 3 weeks. I wish the Petro to come into existence and hope that this project does not get stopped if another president should take office. Venezuela is really doing something revolutionary here and I would like to see how this plays out.
If I were the US though, I would make sure that this project fails in some kind of way... it does not matter how, violent or not... the project from a view from the US is really a danger to a 50 year old privilege. If this privilege comes to an end and many countries place their backed currencies (backed by FIat/Decree), the US looses a lot of power worldwide. This could be seen by a dwindling down of all currencies (especially the Dollar).
Although for that other countries would have to copy the approach from Venezuela. These 5 billion USD are only the first 5 billion... other countries might give out a trillion USD worth of their Petros.