Pros
Schlumberger is a technical leader in the field and provides great training to employees. If you are one of the lucky ones who actually makes is out of the field, it seems like it would be a good company to work for.
Cons
It all depends on where you end up working. Some districts are very good, others are terrible. There is an enormous disconnect between the managers and the field population. Much of this is due to very poor communication from the top down within our district. Management seems to be very hasty in decision making without thinking first about the long term consequences of the decisions. An example of this would be in moving the local managers to Houston (4 hours away.) Many employees have either never met their manager in person, or only see them 1-2 times per year. Now 2 years later they are realizing that it is bad for managers to be so far from their employees, when this should have been immediately apparent. The schedule with this job can be very unpredictable to the point of almost being non existent. In order to cope with this you must be a flexible person. Depending on your family status, this can be difficult at times.