Yemen LNG Operational feedbacks

Transcription

1 Yemen LNG Operational feedbacks APCI Owners Seminar XI September

2 Yemen LNG - Agenda 1. Yemen LNG general presentation 2. Feedback on Plant restarts optimization 3. Other operational feedbacks 2

3 YEMEN LNG GENERAL PRESENTATION Shareholdersh OPCO / Total Technical Leader (39.6%) 3

4 YEMEN LNG GENERAL PRESENTATION Key project data Yemen largest industrial project 6.9 Mtpa Average 110 LNG cargoes per year Project Milestones: o o o o 1995: First GDA 2004: FID 2005: Site construction started Sept. 2009: Train 1 First LNG on 15 Oct. First export on 7 Nov Sales Contracts / 20 years TOTAL KOGAS GDF SUEZ 4

5 YEMEN LNG GENERAL PRESENTATION Upstream Facilities Transfer line 25 km 30 Main line km Gas supply to the LNG plant LNG Plant: 2 trains & terminal 5

6 YEMEN LNG GENERAL PRESENTATION 38 Pipeline profile 1000 m Transfer Line Sand dunes 1400 m Ascent Plateau 1700 m Descent 0 CPU 0 KPU Main Line Wadi & sand Plateau Ascent Plateau Descent BalHaf Basalt 6

7 YEMEN LNG GENERAL PRESENTATION Main line 7

8 YEMEN LNG GENERAL PRESENTATION Process description 2 identical trains design capacity of 6.9 Mtpa (6.7 guaranteed) Gas Pre-treatment: AGRU (Amine unit) Dehydration (molecular sieve) (Mercury bed) APCI C3-MR split process 2 spool wound type Main Cryogenic Heat exchanger (MCHE) of a guaranteed capacity to produce t/h per train (APCI) 2 MR and Propane compression packages ( Eliott) 4 Frame 7EA turbine packages driving refrigerant compressors (General Electric) 2 LNG storage tanks (2 x m3) 1J Jetty for up to 205, m3 vessels 8

9 YEMEN LNG GENERAL PRESENTATION Feed Gas Composition VV Lean V Lean Rich Component (Mol %) (Mol %) (Mol %) H H2S N CO C C C IC NC IC NC NC NC HHV ( ) ( ) ( ) 9

10 YEMEN LNG GENERAL PRESENTATION Key Figures 82% Yemenis in Operations teams Average of 170 expats on site ISO certification for Laboratory ISO certification ISRS Level 5 Indicators Design 1 Jan- 31 Jul 2013 LTIF TRIR RDL Production 445 t/h 465 t/h Reliability 99.5% ** Availability 95% * 96.0% ** Thermal efficiency 90.4% * 90.6% ** 10 * Target for 2013 ** Up to 31 st July 2013

11 FEEDBACK ON PLANT RESTARTS Shutdown events Plant restart duration 9 MCHE bottom temperature before restart (average 2 trains) 40 Num mber of days days saved Estimation (feed gas limi ted) MCHE bottom temperatur re (degc) 11 Note: Plant restart duration is from Pipeline pressurization to the 2 trains at full production

12 FEEDBACK ON PLANT RESTARTS Typical start-up t sequence Restart sequence 5 days Pipeline re-pressurization Trains restart 8h 12h 12h 24 to 36h 1 st Train Warm end restart => Gas on spec ready for cold end Pre cooldown => 30 C ready to start MR circulation Final cooldown => 1st LNG drop 144 C) Ramp up => maximum sustainable production (optimized process conditions) nd 2 nd Train Train 2 ramp up can be slow down due to Ethane shortage 12

13 FEEDBACK ON PLANT RESTARTS Optimization i of the restart t sequence Main challenges: - Pipeline re-pressurization - Restart sequence: Not possible to restart 2 trains at the same time (flare design) - Lean gas composition and Ethane inventory limitations Several axis of progress: Warm end restart Pre cooldown Final cooldown Ramp up Optimization of the inter-steps Pipeline pressurization and warm end restart almost Anticipation in parallel of the restart: Anticipation preparation of next during step shutdown Feedback tools Optimization i of each hstep 13

14 FEEDBACK ON PLANT RESTARTS Pre-restart t and Inter-steps t Reduction of the gap between 2 steps Coordination / planning PR and MR compressors restart anticipated Lessons learnt: Feedback before & after restart Good improvement : No gap between 2 consecutive steps Gain on the overall planning = 2 hours Pressurization Pressure optimization in the upstream sections < 70 barg From upstream and downstream sections at the same time Improvement = re-pressurization duration reduced by 10 hours 14

15 FEEDBACK ON PLANT RESTARTS MCHE pre-cooldown MCHE pre-cooldown to -30 degc Optimization of the cool down flow: Flow through MCHE is restricted by PV on shell side Optimization done by early opening of the JTs and drains Increased feed gas flow Homogeneous cooldown of the MCHE HP MR separator and lines up to MCHE Early cooldown recommended Done during pre-cooldown to be ready for final cooldown Gain on the overall planning = 10 hours LNG FEED GAS NGL REINJECTION MCHE HP MR sep 15

16 FEEDBACK ON PLANT RESTARTS MCHE final-cooldown ld Citi Critical step: degc Not possible to decrease the duration Nevertheless some optimizations done Control of the cooldown rate Material constraint = 28 deg/h maximum Temperature control difficult when the MR starts condensing LMR PDI VMR PDI Monitoring with the VMR & LMR coils PDIs Feed Gas flow adjustment 16

17 FEEDBACK ON PLANT RESTARTS Ethane management Major impact on the restart sequence: Very difficult to start LNG production without C2 in the MR loop Ramp-up strongly impacted by C2 shortage Lean feed gas composition Long time to build C2 inventory Minimum level to be kept in the C2 bullet at any time Recommendation during restart C2 make up sent tdirectly from de-c2 to MR loop C2 from C2 bullet: Priority for the 1 st Train To be be re-started as early as possible To produce C2 for the 2 nd Train 17

18 FEEDBACK ON PLANT RESTARTS End flash gas unit re-start t By design, no by pass of the EFG unit At least 4 hours required to cooldown the LNG pumps and End Flash drum Anticipation: During plant ramp-down: maximize the level in the EFG drum During plant shutdown: Monitor level in the EFG drum If required re-filling operations by reverse flow from the RDL Gain on the overall planning = 4 hours 18

19 FEEDBACK ON PLANT RESTARTS Plant ramp down and shutdown Pipeline de-pressurization and plant ramp down check list including: 1 train immediately stopped 1 train producing until pressure at CRF is 50 bara Minimum to operate the train Ease to PPL re-pressurization C2 inventory maximized during ramp-down Driers sequence stopped at the end of cycle 1 fresh drier ready for restart Plant shutdown Amine unit Amine circulation stopped to avoid gas losses through amine flash drum Filtration is kept running 19

20 FEEDBACK ON PLANT RESTARTS Restarts t optimization i - Conclusion 7 restarts t for both Trains Good improvement of the restart sequence, reduced by 1.2 days High level of experience of operators on restart operations Way forward: Keep the knowledge for next restarts Reduction of the flaring during re-start MR composition adjustment due to MCHE leak PV at the top of MCHE shell connected to the fuel gas network Not used because mainly N2 is vented To reduce C1 content in MR loop: HP MR separator is used Modification on-going to re-route this line to the fuel gas network (instead of flare) 20

21 OTHER OPERATIONAL FEEDBACKS Train 2 planned SD in May 2014 The biggest planned shutdown ever planned All the initial scope completed (Main: turbines HGPI*) 2 days ahead the schedule (6th May to 17th May 2013) Zero accident Frame 7 Hot Gas Path Inspection: turbines in very good condition 48 Vessels, Furnaces and Heat exchangers inspected (no major issue) Inlet orifice replaced on Train 2 Driers beds changed out ESDV downgraded situation rectified Elliot Compressors: replacement of 6 conical start up strainers by spacers * HGPI: Hot Gas Path Inspection 21

22 OTHER OPERATIONAL FEEDBACKS Train 2 Implementation ti of new venturi Benefits of reducing pressure drop: Increase the pipeline capacity Bigger buffer effect (packing/depacking) Fuel gas savings at Upstream Design flow rate Design DP 22

23 Yemen LNG Operational feedbacks THANK YOU APCI conference September