photo of an W?rtsil? engineer

W?rtsil? is incorporating its offshore services experiences and best practices into a ‘modular engineering concept’ that will make it easier to find solutions in the future. (Photo by Michele Rossi, 2009, courtesy of W?rtsil? Corp.)

Rig operators can maximize the efficiency of their operations while avoiding downtime with the help of asset management strategies that include well-planned power management upgrades. Maritime power management specialists are increasingly finding ways to help rig operators improve the efficiency of their electrical and automation (E&A) systems through onsite upgrades even in remote locations, with no need for costly trips to distant dockyards.

"Running electrical and automation systems is like running a computer, since over time they start to work less efficiently, and components eventually become obsolete when their maintenance is no longer supported," Ari-Pekka Saarikangas, director, Electrical & Automation at Wartsila Services explained. "To maximize the overall cost effectiveness of operations, it's important to run regular E&A upgrades. Planning and scheduling upgrades proactively can minimize the time when assets are out of operation and avoid expensive surprises when an obsolete component suddenly has to be replaced."

A new technical management approach

The Services division at Wartsila Corp. provides support for offshore operations through a new kind of technical management agreement designed to ensure that engines and power systems will constantly run optimally.

According to Tage Klockars, general manager, Wartsila Service Agreements Marine, "This kind of technical management involves installing high-tech electrical and automation equipment in a rig's control room to enable the continual online monitoring of conditions on the rig."

Wartsila has been using such experiences to develop a "modular engineering concept" that will make it easier to find solutions in the future. "We're building up best practices that we can embed in modular solutions to help customers achieve seamless transitions during upgrades, modernizations, and conversions," Peter Lee, general manager, Global Oil and Gas, said. "Best practices derived from our proven offshore applications, together with customer feedback, can form the basis of modular solutions with an 80/20 approach." Lee said about 80% of a solution can be built up from tried and tested engineering modules, while the remaining crucial 20% will consist of customized solutions designed through close collaboration between the company's technical development, engineering, and sales personnel and customers.

"Getting customers involved in project management gives us a vital understanding of how each system works, what we can do while it's running, and exactly when we can go in to execute so as to minimize disturbance to operations," he added.

Wartsila is currently developing modular solutions for offshore applications including integrated control and safety systems, fire and gas safety systems, and emergency shutdown systems as well as power management systems. Lee compared the idea to building blocks. "Complex electrical and automation systems often fail due to problems at their interfaces," he said.

"Modular solutions create seamless connections between different systems. This reduces risks, costs, and execution times, also allowing repeatability and scalability for future operations and maintenance."

Dynamic maintenance planning

According to Klockars, constant monitoring enables comprehensive dynamic maintenance planning based on actual conditions. The online systems, for example, transmit real-time data to Wartsila's Condition Based Maintenance Center in Vaasa, Finland. These data are analyzed monthly to create summary reports and updated recommendations. "We also give six-month predictions for future maintenance needs," Klockars said. Selected components are additionally inspected visually on a periodical basis in tandem with the training of the rig crew. Data from the online condition monitoring of rig thrusters are sent to the company's Propulsion Condition Monitoring System Center in Holland. The resultant data from all these sources allow Wartsila to closely monitor the actual condition of vital equipment.

"Such technical management agreements are typically made for a minimum of five years, plus an optional five-year extension," Klockars said. "The benefits to customers include reduced fuel and maintenance costs, the prolonged lifetimes of components, savings on the time spent by rig crew on monitoring and maintenance, and fewer unplanned stoppages due to component failures and unscheduled maintenance work."

Successful onsite upgrade at sea

In 2010, Wartsila Services Australia carried out a major power management system upgrade on the Nan Hai VI semisubmersible exploration and appraisal drilling rig in the Carnarvon basin offshore Western Australia. The rig, owned by Chinese Oilfield Services Ltd. (COSL) and managed by Maersk Drilling Australia, had started to suffer from power problems in 2009 while prospecting for oil beneath the Indian Ocean. "We realized we needed to replace the engine control system because of its obsolete parts and the lack of knowledge to enable field engineers to service existing equipment," Ulrich Neumann, technical superintendent, Maersk Drilling Australia, said.

Maersk Drilling and COSL challenged Wartsila to identify the root causes of the power management problems and find ways to resolve these issues without interrupting drilling. Such an upgrade project would normally involve towing the rig to a dockyard in Asia for a layup of several weeks.

"Careful planning coupled with our technical and project management expertise enabled us to propose an optimized solution," said Venkata Srinivasan, E&A engineering manager of Wartsila Services in Australia. Taking only one engine offline at a time and working within the available window periods, the work was successfully completed in approximately three months without interrupting drilling.

Overcoming challenges

The rig's four 28-year-old 1.8 MW diesel engines required complete overhauls, and the four sets of engine controls, generator controls, and governors needed to be replaced.

Limited space on the rig was a considerable challenge in terms of finding storage space for the almost four tonnes of machinery and equipment needed for the upgrade and accommodating the servicing team members. Wartsila had to carefully map out the project stages to ensure that the necessary equipment and the team members with the right skills were all onboard the rig at the right time.

"On the basis of a detailed technical audit of the rig's obsolete power management systems, which had limited documentation, our team carefully studied the issues they had with the present system and came up with a detailed report and recommendations for the customer on the components that needed to be replaced or upgraded," Wartsila Australia Technical Manager Matt Riley said.

The Nan Hai VI's revamped power system incorporates a SCADA system featuring two Wartsila Operator Interface Stations (WOIS), whose LCD screens enable the constant monitoring and touch-screen operational control of the rig's power source.

Completing this kind of upgrade while enabling a rig to continue uninterrupted drilling in its offshore location can result in substantial savings for customers. According to David Roberts, sales manager at Wartsila Australia, well planned and executed onsite upgrade projects can avoid downtime that would effectively cost millions of dollars.

Maersk Drilling also was satisfied the upgrade could be successfully planned and executed while the rig remained fully operational. "The rig's new reliable electricity supply will be the basis for the safe and successful operation of Nan Hai VI in the future," Neumann said.