NAM (Nederlandse Aardolie Maatschappij), a joint venture between Royal Dutch Shell and ExxonMobil, originated in the mid-1990s. Its goal was to find the most cost-effective way to extract the gas and extend the life of its reserves, ensuring the gas field could continue to supply the region.
The Dutch Groningen Field is Europe’s largest natural gas field, which has been a reliable source of energy and greater energy diversity across the Netherlands and Europe for 50 years.
The field uses 29 production installations spread over the field in 14 king size clusters and 15 standard size clusters.
As the volume of the gas had been depleted by as much as 50% in the 1960s there was an immediate need to extend the reserves of the Groningen Field. With free-flow production rapidly decreasing, NAM decided to bring all of the installations up to date by installing compressors, renovating the existing equipment and adding a new process control system.
The success of this project was a result of teamwork, technology and long term thinking by NAM GLT, Gasunie, Shell, ExxonMobil, and a consortium including Waukesha Magnetic Bearings.
Henk Niezen, Project Director, and Wim de Groot, Rotating Equipment Engineer of NAM GLT, share their experience working on the NAM project and their decision to implement a compression string using magnetic bearings systems provided by Waukesha Magnetic Bearings.
This field is so large that it can deliver for around 40 years for all the households here in the Netherlands and also exports to Germany and Belgium. It started initially with around 350 barrels in the reservoir and it has declined over the years now to around I would say 100 barrels. This means this field that has been built around the years 70s has to be renovated fully – all the 29 sites had to be replaced by modern new technology, modern controls and most important compressors.
“Traditionally companies like NAM and Shell or Exxon Mobile who was our partner in NAM, were risk adverse to these extents but I would say for the magnetic bearing system in compression stings this is no longer the case. This is now proven technology.”
“The NAM-GLT contract is a good example of our ability to partner with the OEM and users. In that instance we worked with NAM to sit together and determine what is required to make these machines work reliably over a long period of time.”
Technology leadership is at the forefront of every Waukesha magnetic bearing system. The custom engineered system for the NAM project is a good example of that.
“The NAM GLT bearing system has the magnetic bearings and auxiliary bearings of unprecedented size. You can see behind me the motor bearing for the NAM project the magnetic bearing for this application is 550mm in diameter and the auxiliary bearing bore is 450mm in diameter.”
There are many advantages of installing a magnetic bearing system from Waukesha – including its software functionality enabled by remote connectivity capabilities.
“All our controllers are equipped with a web interface and that means that so long as we have a suitable TCP/IP transport mechanism that we can log into our systems remotely from anywhere in the world.”
Waukesha Magnetic Bearings has achieved reliability and availability that is unmatched in the field.
“Looking at the reliability and compare it to with what we expected 15 years ago, it came out to be better, surprisingly better than we expected. The reason for that of course, we renovated all the installation and the controls, but also the performance of the compressor itself was so much better and it has a very good records and it has partly to do with the magnetic bearings and its own reliability. But also the simplicity of the whole design.
“It meant that a lot of the traditional equipment that you have around a compression string like lubrication systems and other oil systems were no longer present and because of that, it would reduce the amount of auxiliary equipment around the compression string a lot.”
The reliability is of most importance because of costs because we have to deliver the gas at the moment that it is asked. If the operator push the button to increase or stop the flow it must be done directly and with such a new system, mind you 23 megawatts with 25 compressors in the field all have to operate simultaneously in this way.”
“Traditional compression string would have an average of 87% availability and that is already high, and here we’ve reached over 95, sometimes 96-97% with a reliability over 99% and that is very, very good for a compression string.”
With over 30 years of installations in the field, magnetic bearings prove to be the lowest cost solution over the life of turbomachines.
The total cost of ownership we calculate it by the efficiencies of the compressor both at full load and low load. that means a 23 megawatt compressor will run maybe 70-80% of the time and not be above 7 megawatts. That saves us a lot of energy. We made the calculations based on the amount of energy you saved if you could run at part loads over 35 years and then you see immediately that it has an enormous impact on your costs.”
“A solution with magnetic bearings saved us a lot of investment cost – about 35% eventually, and on life cycle costs it was a tremendous amount of savings that we could make all to the benefit of the combination where magnetic bearings played a key role in this whole set-up.”
“I think it was very clear to Waukesha what our reputation was and how important a robust reliable compressor was to us and I think they contribute together with Siemens to find the best solution for us.”
“I think that we only see the beginning of the technology and the capabilities of magnetic bearings, I think there is a whole bright future ahead with this new technology applied in equipment in the oil and gas industry.”
“Whatever your do, in the end it’s the performance that counts. When I look at the performance it’s really amazingly good."