The Northsea Oil/Gas Field

Transcription

1 National Kaohsiung First University of Science & Technology Kaohsiung, the Harbor City in Taiwan Challenges of Offshore Emergency Response: from Piper- Alpha Platform to Chemical Tankers Incidents Jenq-Renn Chen( 陳政任 ) jrc@nkfust.edu.tw Dean, College of Engineering, Distinguished Prof., Dept. of Safety, Health and Envir. Eng. National Kaohsiung First University of Science & Technology Director, EPA Southern Environmental Response Team Kaohsiung, TAIWAN Kaohsiung Taipei The Northsea Oil/Gas Field You can't connect the dots looking forward; you can only connect them looking backwards. So you have to trust that the dots will somehow connect in your future. You have to trust in something your gut, destiny, life, karma, whatever. Steve Jobs,

2 Platforms & Network Functions of Piper Platform 5 6 July 6, 1988, a small explosion occurred July 6, 1988, a small explosion occurred 226 people onboard Operator re-started a pump with a relief valve removed and replaced by a loose flange causing a release of condensate, followed by an explosion The explosion damaged the fire wall, and the fire pump Fire engulfed the platform 7 8

3 July 6, 1988, a small explosion occurred July 6, 1988, a small explosion occurred 9 10 The major explosion 11 12

4 Release rate from rupture of gas line Pressure at intact end At MCP-01 platform Release rate from the MCP rise on Piper platform The aftermess A total of 165 people on Piper died The explosion from rupture of MCP- 01 rise destroyed the rescue boat, killed 4 survivors onboard the as well as 2 crews The fireball rolled across the water and people standing on the deck of the Tharos platform were thrown down Chen, J. R., Richardson, S. M. and Saville, G., Numerical simulation of full-bore ruptures of pipelines containing perfect gases. Trans. Instn chem. Engrs 70B, 59-69, Lessons learned from Pipe-Alpha Safety is the first priority for offshore oil/gas installations Safety must be implemented through management as well design that prevent or mitigate the release of flammable mass Emergency response to any incident on open sea was in particular a very challenge job 15 On Feb 19 night, 2012, MT Oberon ran aground near the lighthouse Inclination Mutou Island 3/06 owing to strong monsoon wind. All crew were rescued by helicopter leaving 1,061 MT butene onboard. 1.4 m Nearly full tide!!!

5 M/T Oberon Properties of 1-Butene Type Length Width Speed (avg/max) Cargo Capacity LPG tanker 93.0 m 15.0 m 1.6 / 9.5 mi 2,980 mt Flammability limits =1.6~9.3% PEL= none Acute action: gas is an asphyxiant, frostbite or freezing may occur when contacting liquid Boiling point:-6.25 C Vapor C: 1.62 kg/cm 2 G Liquid sp. C :0.595 Total content: 1061 MT Year of built 1984 Fuel oil 45 MT Diesel oil 10 MT /2/20 Fail to onboard 2012/2/21Fail to onboard

6 2012/2/22 First onboard Detecting Butene Vapor pressure of butene Vapor temp:24.8 C Liquid temp:13.5 C Pressure:2.5 kg/cm 2 Tank pressure is slightly higher than liquid vapor pressure, a result of N2 purge after loading

7 2012/2/23 Onboard for leak patching Heavy fog, visibility is low ~ 10 m Leaking from valve gland packing Frost indicating leaking Leak identified by soap water Leak patched with epoxy

8 Actions following patching Oil spill onshore cleaned by end of March Remove all remaining fuel oil onboard done by end of March Regular onboard to check leak and cargo status Cargo removal and wreck removal Ice melted after leak patch 30 Tank design pressure:18.6 kg/cm2 Piping design pressure:20.0 kg/cm2 Tank volume:1250 m3 Shell plate thickness:45 mm End plate thickness:23 mm

9 Main Issues What can happen before cargo removal? How to remove cargo butene? When to remove cargo butene? What are the risks for cargo removal? Risks before cargo removal Tanker orientation Deflected but still acceptable Tanker structure integrity Deteriorated but still acceptable Tank and pipeline corrosion Deteriorating and actions required Sounding around Oberon Starboard side distortion Data taken at full tide -2 m for low tide 35 36

10 Starboard side distortion Canopy/skirt distorted and rubber expanded Potential Corrosion risk: Corrosion Where is the leak?

11 Potential risk - Corrosion 2/22 3/02 3/06 3/16 4/19 5/06 Actions taken Variation of tank temperature and pressure Gas detector handed to staffs on the lighthouse for daily monitoring ER staffs onboard every week to perform leak check and patches Temp (C) Liq Temp P (kg/cm2) VP(kg/cm2) Pressure (kg/cm2)

12 Enforcement of Tank 2 Cargo removal risks/problems Weather Shallow water How to connect hoses How to pump out liquid butene Pump or compressor? Communication/coordination Compressor room is intact Oberon location 48

13 Cargo removal plan by Resolve/Seagreen Ship-to-ship transfer 4 point mooring Jack up barge to support hoses Use pump at Oberon Jack-up Barge arrived Longmen Winch and wire for supporting hoses Liquid nitrogen and evaporator

14 Anchors & buoys for mooring, & hoses with supports Sail out Seagreen 15 with Buoys Assembling hoses Pressure testing of hoses

15 Hoses on jack-up barge fixed All hoses ready Oberon as seen from Jibai Island M/T Oberon as seen from lighthouse

16 Jack up arrived near site Group Meeting on Jack-up Jack up Captain Project leader, Seagreen Tug Captain Tug Captain TMC consultant Project leader, Resolve Salvage master, Resolve Relieving anchor and buoys Diver check of anchor

17 Positioning jack up Lifting of Jack up Diver check of support legs Diver check of support legs Supports adjusted accordingly.

18 Ladyship piloted to position by fishing boat Skipper setting up mooring rope Four points mooring completed Cargo Operation Meeting TMC consultant Oberon Captain Project leader, Resolve Ladyship Chief engineer Ladyship Captain Ship-to-ship consultant

19 Connecting hoses Connecting hoses D buckle with wheel Lifting strip Liquid hose (4 ) Vapor hose (3 ) Reinforcing wire support Connecting wire

20 Pushing the hoses Receiving hoses at Ladyship Connect hoses to manifold Hoses ready, transfer started

21 Transfer continued in the night Dawn Sounding of tank Progresses of cargo transfer Generator trip Disconnect hoses Average transfer rate = 1000/38 = 26.3 t/hr

22 Progresses of cargo transfer Risk of weather 5/25 19:15 Liquid valve open, liquid flow by P. 5/25 20:30 Cargo pump at Oberon start, P at Oberon: 5.4 bar, P at Ladyship: 1.3 bar 5/2521:30 Slip tube check: 10 t 5/2521:40 Increase P at Oberon 5/2522:30 Slip tube check: 51 t 5/26 04:30 P at Oberon: 7 bar, P at Ladyship 3 bar 5/26 07:30 P at Oberon: 8 bar, P at Ladyship 3 bar 5/26 09:00 Strong wave, pump stop, line purged, disconnect hoses, ready for depart 5/26 10:40 Reconnect hoses 5/26 10:10 Pump restart, slip tube check 386 t 5/26 14: t, P at Oberon 10 bar 5/26 16:30 Cargo pump trip, resume in 10 min Progresses of cargo transfer Disconnect hoses and vent 5/26 21: t 5/26 21:48 Oberon generator trip, pump stop. Back into operation on 22:00 5/26 22:05 Tug rope from No 7 broken 5/26 23:15 Generator stopped again 5/27 00:20 Pump start again 5/27 01:19 Generator trip again 5/27 01:58 Start compressor on Ladyship 5/27 05:00 Pump restart, P increase to 12 bar, compressor off 5/27 09:25 Generator cooling fan belt broken. 987 t done. Use N2 to push remaining liquid out 5/27 10:35 All liquid out, t, Oberon tanks pressurized by nitrogen to 8 bar 05/27 12:30 hose disconnected 05/27 13:20 Ladyship depart for Taichung

23 Hoses retreated to Jack-up Release mooring rope Sail out of Ladyship Hoses retreated from Oberon

24 Conclusions All butene was removed without major leak or injury, despite various mechanical and weather problems. Good teamwork, communication, coordination from Resolve, Seagreen, and local participants contributed to the successful cargo removal work Oberon wreck removal was done at end of August Department of Safety, Health and Environmental Engineering Thank you for your attention!!! National Kaohsiung First University of Science & Technology 93