For the very first time, Statoil is replacing the control system in older wells on subsea fields. The next generation of technology will enable the feisty ladies, Vigdis and Tordis, to keep on working 15 years longer than expected.
All of the wells on the Tordis and Vigdis fields will be getting new control systems during 2012. (Photos: Marit Hommedal)
Retirement won’t come for the venerable ladies until 2030.
The first wells with a new control system on the Tordis subsea field in the North Sea were transferred to operations at the turn of the year 2011/2012. All of the wells on the Tordis and Vigdis fields will be getting new control systems this year.
“This will mean a new lease on life for the productive ladies, and even more years of production,” says Joar Kristensen, project manager for Tordis/Vigdis Control System Modifications (TVCM).
“Statoil is the first company to use GE Oil & Gas’ new and advanced control system for subsea fields called SemStar 5, based on fibre optics and internet technology. The system is adapted to us who are the primary users and our test requirements have been part of the equipment qualification. Statoil has cooperated closely with GE in the development process.”
The new control system can be monitored and operated from land, and includes equipment that makes it possible to diagnose seabed equipment in real-time. The new solution will be more reliable and will increase well uptime. The control system includes both sand monitoring and leak detection, and additional functions can also be built into the system.
Operations to 2030
“The upgrade is required to maintain Statoil’s ambition to keep the fields operating until around 2030. Initially, the technology will be installed on the 26 wells tied to the Tordis and Vigdis fields.
The experience we gain in this process will come in handy as we now start to look into similar upgrades on other subsea fields . Another much-appreciated aspect is the transition to a more environment-friendly hydraulic fluid,” says Kristensen.
Easier to monitor
“The control system is built on the technology of the future, with all the opportunities this entails. While in the past we had to be physically present to repair faults and make adjustments to the control system, we can now monitor and support the process from land,” says Christian Svennevik Skaar in technical operations support on Tordis.
“Sand and leak detection are examples of functionality that will make our daily work easier and safer, and will allow us to optimise production.”
Doing it all for the ladies
The past few weeks have been hectic for the project team.
“A lot of activity on the field in parallel with the introduction of new technology demands steady coordination. We are well-prepared and ready to give our all for the “ladies”. Knowing that Tordis and Vigdis will be more robust and more functional is our best motivation,” says Kristensen.
Tordis, which started producing in 1994, sends oil to the Gullfaks C platform while Vigdis, established in 1997, sends its oil to the Snorre A platform. Like many other subsea fields on the Norwegian continental shelf, they have helped extend the lifetime of platforms and pipelines. Today, we have recovered 48% of the oil on Tordis, and 38% of the oil on Vigdis. This is 300 million barrels more than was expected when the development was planned. Now, the new control system is making it possible to further extend the lifetime and functionality of the wells.
|GE Oil & Gas|
GE Oil & Gas is a world leader in advanced technology equipment and services for all segments of the oil and gas industry.
33,000 employees in 130 countries.
Centre of excellence for subsea systems in Norway.
|Facts about TVCM|
• Project approved (DG3) in June 2009
• Expected completion in October 2012
• Ambitions for increased reliability, extended lifetime, new functionality and opportunities for future expansion
• First to use the new SemStar5 technology from GE Oil & Gas
|Facts about SemStar5|
• GE VetcoGray’s fifth generation control system for subsea production systems
• Uses the ethernet and TCP/IP
• Flexible communication solutions (fibre, RS-422 and copper modem technology, etc.)
• Redundant system: if one component fails, an identical one will automatically take over