They only hire through staffing agencies. Elwood staffing (formerly SOS Staffing) is their primary one. After a 90 day probation period you are eligible to be hired on directly by Schlumberger. Lab techs at most locations get rolled over pretty quick (the process usually starts before the 90 day probation period is over for lab techs). I've heard of people in field positions being forced to wait as long as a year before being rolled over though. My interview was pretty straight forward with only standard interview questions being asked.

Applied online with the staffing agency (SOS Staffing) and received a call for a phone interview less than a day later. A few days after that I had another phone interview scheduled. This one lasted about 15 minutes and included mainly behavioral type questions. They scheduled an in person interview several weeks out. That interview was in a hotel meeting room with 13 other candidates, 4-6 Schlumberger folks, and 2-3 of the SOS staff. They did about a 45 minute presentation on the company and how grueling the work would be; that we would miss birthdays, weddings, celebrations, holidays, and work weekends and very long hours. They then split up and called the candidates out one by one for interviews. Mine lasted approximately 3 minutes. The Schlumberger guy asked me maybe three questions and then wanted to know if I had any questions. They called me back late (8pm) the next day to offer to continue the hiring process. From there I did three drug tests (hair, urine, breath), a pulmonary function check, hearing test, and later a physical fitness check. Had to drive long distances for all of these things. Waited and waited for information from the recruiter that never arrived. Was later told recruiter no longer worked with the company. Got final word of start date the Friday before I was to start work. Very stressful process with extremely limited information flow.