Is it hard to obtain a job in Petroleum Engineering ?

YES IF YOUR AREA HAS NO MAJOR PETROLEUM INDUSTRY.

It's hard to obtain an entry-level job, because too many students are now majoring in this discipline. The "oil bust" also created problems for experienced petro engineers, but oil prices have since stabilized, so it's pretty easy to find a job if you've already established a decent resume in the field. MOST petro engineering students will be able to find jobs because about 1000 per year are retiring from the field, but the growth in labor requirements is not enough to employ ALL the rest of the ~1500 new BS grads per year (US figures).

It is generally hard to obtain ANY job.

That is why you have to give yourself an edge through education or specialization.

Present your future employer with something they need but cannot get so easily with someone else.

Good luck