A core safety challenge in drilling operations is to control the drilling process by retrieving the necessary data, interpreting it and comparing it to existing plans and models of the operations. With more and better sensors and improved transmission channels in the drill string, the amount of data in drilling operations has increased significantly. One aspect of drilling operations that many of the informants pointed to as characteristic was the amount, availability and quality of drilling data and background geological data. Another characteristic of drilling operations highlighted by many informants is the organisation of knowledge work within the organisation. A central point is the comprehensive outsourcing of analysing work to service companies. The controversies identified are not only descriptive for today’s drilling operations. In change processes, many features of the ‘old’ regime have a tendency to deposit rather than disappear.