I'm not from petroleum, so can't get you specific input you want.
Please see this link for sample syllabus,
http://umat.edu.gh/petroleum-engineering.html?start=3
There is briefly describe what you will study in the future.

For buying reference book or any book, I recommend Book Depository Online.
It's UK based online store, provide free shipping worldwide, and the price is lower than what you can get in M'sia.

(Color vision deficiency) Color blindness not an issue to become petroleum engineer. Even visual impaired can become engineer.
There is no discrimination on color vision deficiency, but you have to know your own limit.
But depends on the company whether if they want to hire or not, if the job need perfect eyesight, then you have no chance on that certain job. You may try in another company.

Do you have this issue?

“If you are faced with a mountain, you have several options.
You can climb it and cross to the other side.
You can go around it.
You can dig under it.
You can fly over it.
You can blow it up.
You can ignore it and pretend it’s not there.
You can turn around and go back the way you came.
Or you can stay on the mountain and make it your home.”
― Vera Nazarian

Why give up when you interested in it?
Please take a look in the video below.