I was recruited by an external recruiter. Then there were multiple calls before they flew me to Houston for a group interview.
They drug test, both urine and hair follicle.
The group interview was 2 days and consisted of group projects, group situations to see how social you were, and an individual interview.
They also had lots of propaganda telling you how great Schlumberger is. They tell you about the opportunities (which are BS). They tell you so many lies and false truths that it's ridiculous. Don't believe anything they say, you don't have opportunities at Schlumberger. You will work for Geoservices, a dysfunctional company owned by Schlumberger.
The interview is a long process, but they hire almost everyone (unless you are a total idiot). They are desperate for people because of the high turnover.
They also offer moving expenses and signing (moving) bonus. DON'T TAKE IT. If you quit before a year you have to pay it back. IT'S A TRAP. They own you for a year. Don't be a sucker.
Best advice: Don't work here. Keep looking.