This paper describes the evolution of scientific softwares applied to ELF AQUITAINE's drilling operations.
Starting from an historically scattered situation, it points out how strategic decisions taken by the company have led to the development of a framework.
This framework, called CALPIN, set up to receive and integrate scientific programs, is now operational. It contains numerous softwares, including expert systems which are useful for drilling planning on operational bases and also help decision-making, directly on the rigsite.
The development guidelines as well as the solutions adopted are described in detail. The modular structure of the development allows for easy maintenance of the system and favours its evolution. In particular, it is easy to integrate a new software in the framework. Open to the outside, CALPIN enables the user to be connected with nearby data bases and to process his own data files by means of independent data-processing tools.