petroleum engineering is a useful thing or not
Is this your desired branch or do you have interest in that?
Also, you can check the scope for the same given below -
The Oil & Gas Industry is a cyclical one. If you can ride through the low tides and cash in during the high ones, petroleum engineering is the right choice for you.
Having said that, PE can get placed in PSUs (in India via GATE) and other private companies like Schlumberger, Shell, Cairn etc. The post of a petroleum engineer is a lucrative one, considering the humongous packages that they earn.
Good Luck!!!