At the end of 1995, a number of oil companies organised a workshop on permanent downhole instrumentation. One of the important conclusions of this workshop was that the operating companies foresaw that in the (near) future multiple monitoring and control devices will be placed in a well. Such a well is designated as an intelligent well.
For such a well it was deemed essential that downhole instrumentation as well as wellhead monitoring systems and control elements could be connected to a single read-out and control unit. The target was a flexible system with a compatible power supply and data communication protocol; avoiding high cost for developing interfaces for the operators, and insuring that new devices could be used within existing system infrastructures without the need to adjust interfaces. Finally, by the agreement on a common data and energy transmission method, the effort required by operators and the service industry introducing such new technology could be minimised.
During the kick-off workshop a task force was formed, consisting of Shell, SAGA and Statoil. This task force has investigated to which extent standardisation is required and how this can be achieved in the most effective and efficient way. The task force initiated the “Intelligent Well Instrumentation Standardisation” project, or its acronym, the IWIS project. The IWIS project was rated as ‘very important’ with the final objective “to arrive at recommended practices to ensure compatibility in data and energy transmission for intelligent wells”.
In March 1996, the task force presented the IWIS project to all the participating oil companies, being BP, AGIP, ELF, STATOIL, SAGA, Norsk Hydro and Shell. This consortium gathered into the PMSC, Project Management Steering Committee, which took the following decisions with respect to the project. In order to do “one step at a time”, the scope of the project was limited to:
- the data and energy protocols and not to develop or test any hardware;
- electrical data and energy transmission, so optical fibres for data communication and other means of transferring power downhole are not investigated;
- protocols for the down hole instrumentation/environment and the project will not formulate these for well head or surface equipment.
The recommendations took into account as much as possible the current practices for surface equipment and focussed on compatibility rather than rigid standardisation. Limiting constraints, which might limit new developments, should be as flexible as possible. Besides the definition of the requirements and specifications for a data and power protocol, the service industry were open about their plans and initiatives and also stated the importance of a compatible way of transferring data and power from the control pod downhole.
The IWIS Recommended Practice was finalised at the September 2007 workshop. This is now available to industry in support of ISO 13628 – 6.