Process was very straight forward. Applied online and submitted a CV. No cover letter required. Talked to one of the engineering recruiters at my university's careers fair. She passed on her contact card and took my CV. I later received an email for an invite to an assessment centre in Aberdeen. The assessment centre consisted of an introduction to Schlumberger and how their business operates. Be prepared to ask questions and answer queries regarding the companies history. There were timed IQ style tests that lasted approximately 1 hr. It is key to be prepared at this stage and make sure to practice as much as possible. There were no numerical style questions. One of the tests consisted of 3x3 matrices where you have to discover a pattern in a small amount of time. Later we carried out our self-presentations that were prepared in advance and assembled a valve with an interview to follow.