FMEA Proving Trials and Offloading Simulations Lessons Learned Arjen Tjallema Bluewater Energy Services BV Douwe Stapersma Delft University of Technology
Agenda p. 2 Introduction FPSO Munin Soliton Currents FMEA Proving Trials Offloading Simulations Supporting the DP Operator Conclusion
Introduction p. 3 In 2004 similar operation at XiJiang, but: Shorter period: outside soliton season Different crew FPSO Munin replaces other FPSO Station keeping by DP only Operation will last 1.5 years
Introduction p. 4 hold-back tug pulls tanker astern shuttle tanker passively moored hawser 20-50 mt pull FPSO Munin DP station keeping 11/09/2010
Introduction p. 5 Munin operating on field as of March 2010 FPSO on DP uncommon, especially in combination with non-dp shuttle tankers Crew not experienced with these operations FPSO and crew prepared by: - FMEA Proving Trials - Offloading Simulation Training 11/09/2010
FPSO Munin
FPSO Munin p. 7 Free rotation around outrigger Outrigger with connected buoy Buoy hold-back chain 2 x production riser
FPSO Munin p. 8 11/09/2010
FPSO Munin p. 9
FPSO Munin p. 10 main diesel generators (4 x 5.5 MW) harbour diesel generator (1.1 MW) bow tunnel thrusters (2 x 2 MW) azimuthing thruster (3 MW) azimuthing thruster (3 MW) propulsion motors main propeller ( 2 x 6 MW)
Soliton Currents
Soliton Currents p. 12
Soliton Currents p. 13 Associated surface current speed: up to 3 kts Travel speed: up to 4 kts Groups of up to 20 Up to 100km wide
Soliton Currents p. 14
FMEA Proving Trials
FMEA Proving Trials p. 16 Trials contained 90 tests, divided over 8 categories: 1. Power Distribution 2. Azimuth Thrusters 3. Tunnel Thrusters 4. Propulsion Motors 5. Power Generation 6. Power Management & Control 7. DP Control System 8. Communications
FMEA Trials Lessons Learned p. 17 main diesel generators (4 x 5.5 MW) harbour diesel generator (1.1 MW) bow tunnel thrusters (2 x 2 MW) confirmed fire in engine room Half black-out test: azimuthing thruster Engine (3 room MW) shut down after confirmed fire azimuthing thruster (3 MW) Half propulsion power lost Switch to tanker mode on vessel control system alarm cannot be reset propulsion motors main propeller ( 2 x 6 MW)
FMEA Trials Lessons Learned p. 18 Crew not fully aware of logic in control systems Wrong decision can be made, as full effects are not clear Alarm flooding makes tracing of the problem difficult and time-consuming In a full black-out test the system recovered very quickly Position loss limited to 5m, however: - In a real black-out there is a cause, which has to be found - Finding the root cause can be time-consuming
FMEA Trials Lessons Learned p. 19 Monsoon conditions encountered Station keeping proved to be very good in high wind speeds, but: heading setpoint is to be chosen carefully or: head with stern into environment
Offloading Simulation Training
Offloading Simulation Training p. 21
Offloading Simulation Training p. 22
Offloading Simulation Training p. 23
Offloading Simulation Training p. 24 When a Soliton approaches, the tandem is to be rotated to head into the current
Offloading Simulation Training p. 25 In first simulations slow tandem rotation due to: - FPSO rotation not optimal - Indirect orders from mooring master - Cautious tug captain
Offloading Simulation Training p. 26 FPSO response after change of heading setpoint: 12 10 heading [deg] 8 6 4 setpoint 2 heading 0 0 50 100 150 200 250 300 350 time [s]
Offloading Simulation Training p. 27 heading heading [deg] 60 50 40 30 20 10 0 0 100 200 300 400 500 600 700 800 time [s] setpoint separate steps heading separate steps setpoint one step heading one step delivered thrust - yaw yaw moment delivered [knm] 80000 60000 40000 20000 0-20000 -40000-60000 0 100 200 300 400 500 600 700 800 time [s] separate steps one step
Offloading Simulation Training p. 28 If the FPSO s rate of turn is too high, the shuttle tanker lags behind This helps rotation of the tanker, but: If it lags too far behind, and the rotation is stopped, position of FPSO is lost! 11/09/2010
Offloading Simulation Training p. 29 hawser pull
Offloading Simulation Training p. 30 hawser pull
Offloading Simulation Training p. 31 Bow thrusters are clear indication for changed current direction When offloading, the shuttle tanker drifts when current changes direction This reduces load on bow thrusters Changing current very hard to detect for operators
Supporting the Operator
Supporting the Operator p. 33 A research project Ultimate Dynamic Positioning (UDP) is currently in progress Project investigates possibility to support DP operators with: - Condition-monitoring to detect problems in an early phase - Operator-support to assist the operator in dealing with problems Lessons learned from FMEA trials and offloading simulations valuable input for research project
Supporting the Operator p. 34 When a piece of equipment fails, it is hard for an operator to find: - What equipment failed - What is the root cause of the problem - How to solve the problem Monitoring and support systems can assist the operator with these tasks Where to put the boundaries of such systems?
Supporting the Operator p. 35 Three criteria to be used: - Sysem s functioning essential? - Can DPO take action in the system? - Is information needed to decide whether or not to continue operation? Operator support system should answer the following questions: - What will be the consequences of a problem - Can the problem be solved rapidly - How to prevent problem propagation - Can the operation safely be continued and how failure condition monitoring alarm operator support advice
Supporting the Operator p. 36 Warn operator in time after detection of problem Assist operator in solving the detected problem failure condition monitoring alarm operator support advice
Conclusion
Conclusion p. 38 Both FMEA trials and Offloading simulations have made the FPSO operate safely and efficiently Understanding the logic in a complex control system can be challenging Therefore effects of operator s actions not always clear can lead to incidents Offloading from a DP FPSO to conventional shuttle tankers requires a special operational approach, especially to change the tandem s heading Changes in current are hard to detect, measurements would be very valuable Condition monitoring and operator support will enhance operator s capabilities in case of unexpected events
Operator support p. 39 Windows was unable to detect your keyboard. Press F1 to retry of F2 to abort Solution Problem Root cause suggested detection found
p. 40 Arjen Tjallema arjen.tjallema@bluewater.com 11/09/2010