FMEA Proving Trials and Offloading Simulations

Transcription

1 FMEA Proving Trials and Offloading Simulations Lessons Learned Arjen Tjallema Bluewater Energy Services BV Douwe Stapersma Delft University of Technology

2 Agenda p. 2 Introduction FPSO Munin Soliton Currents FMEA Proving Trials Offloading Simulations Supporting the DP Operator Conclusion

3 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

4 Introduction p. 4 hold-back tug pulls tanker astern shuttle tanker passively moored hawser mt pull FPSO Munin DP station keeping 11/09/2010

5 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

6 FPSO Munin

7 FPSO Munin p. 7 Free rotation around outrigger Outrigger with connected buoy Buoy hold-back chain 2 x production riser

8 FPSO Munin p. 8 11/09/2010

9 FPSO Munin p. 9

10 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)

11 Soliton Currents

12 Soliton Currents p. 12

13 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

14 Soliton Currents p. 14

15 FMEA Proving Trials

16 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

17 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)

18 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

19 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

20 Offloading Simulation Training

21 Offloading Simulation Training p. 21

22 Offloading Simulation Training p. 22

23 Offloading Simulation Training p. 23

24 Offloading Simulation Training p. 24 When a Soliton approaches, the tandem is to be rotated to head into the current

25 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

26 Offloading Simulation Training p. 26 FPSO response after change of heading setpoint: heading [deg] setpoint 2 heading time [s]

27 Offloading Simulation Training p. 27 heading heading [deg] time [s] setpoint separate steps heading separate steps setpoint one step heading one step delivered thrust - yaw yaw moment delivered [knm] time [s] separate steps one step

28 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

29 Offloading Simulation Training p. 29 hawser pull

30 Offloading Simulation Training p. 30 hawser pull

31 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

32 Supporting the Operator

33 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

34 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?

35 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

36 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

37 Conclusion

38 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

39 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

40 p. 40 Arjen Tjallema 11/09/2010