ELGIN G4 GAS LEAK INCIDENT. 25 March 16 May 2012

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Morgan Mills
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1 ELGIN G4 GAS LEAK INCIDENT 25 March 16 May 2012

2 ELGIN: KEY FACTS & FIGURES Operated by Total for 8 x JV partners Elgin PUQ (Production Utilities Quarters) & wellhead platforms linked by 90m bridge High Temperature/High Pressure fields On stream since 2001 Elgin produces 135k boe/d 2

3 ELGIN G4: WELL ARCHITECTURE On Elgin A (wellhead) platform 93m below platform Chalk HOD non-producing low permeability high pressure Fulmar producing high permeability lower pressure 3

ELGIN G4 GAS LEAK: SEQUENCE OF EVENTS 25 February: sudden decrease of A annulus pressure and rapid increase in B and then C annulus G4 Task Force established: well intervention program with Rowan

4 ELGIN G4 GAS LEAK: SEQUENCE OF EVENTS 25 February: sudden decrease of A annulus pressure and rapid increase in B and then C annulus G4 Task Force established: well intervention program with Rowan Viking rig support 15 March: tubing and A annulus contents displaced to 1.2sg brine March: well intervention start pumping 2.05sg NABM down tubing & up A annulus B & C annuli pressure increase C annulus bled off through WHP process B annulus operating window increased after 172m 3 operation suspended as mud returns to the process via C annulus attempt to re-route C annulus returns line to surge tank sudden unsustainable C & B annuli pressure increase - leading to gas release at well head D annulus Specialist teams mobilised = gas path to surface leak 4

ELGIN G4 GAS LEAK: DAY ONE (25 MARCH) 12.20: gas & condensate leak confirmed at the wellhead on Elgin s G4 well 13.30: evacuation begins of Elgin and the adjacent Rowan Viking drilling rig 16.

5 ELGIN G4 GAS LEAK: DAY ONE (25 MARCH) 12.20: gas & condensate leak confirmed at the wellhead on Elgin s G4 well 13.30: evacuation begins of Elgin and the adjacent Rowan Viking drilling rig 16.40: 219 people have been evacuated, leaving 19 still on the complex 01.45: Elgin OIM decides to fully abandon Platform, rig & wells shut down Export pipelines isolated 02.30: the last 19 people are evacuated All 238 people safely and quickly evacuated 5

Condensate & mud fall to sea Sheen covers a large area

6 ELGIN G4 GAS LEAK: INITIAL IMPACTS Gas, condensate & mud released at deck level Visible gas plume formed Condensate & mud fall to sea Sheen covers a large area of sea surface Waxy paraffinic deposits on wellhead platform 6

7 ELGIN G4 GAS LEAK: INITIAL IMPACTS 7 April surface sheen still visible, but less than 1/10 th micron thick 27 March gas plume and sheen visible, but not obvious 7

8 ELGIN G4 GAS LEAK: SOLUTIONS TO REGAIN WELL CONTROL Preferred solution: pumping in heavy mud a mobile pumping unit putting heavy mud directly into G4 from the wellhead technically feasible re-boarding of the Elgin wellhead platform necessary Wild Well Control already mobilised and suitably experienced no absolute guarantee of success timescale measured in weeks Back-up solution: drilling a relief well a contingency in the event the well pumping intervention is ineffective technically feasible start drilling two wells and use the one that reaches the interception point first two drilling rigs (Rowan Gorilla V & Sedco 714) to be mobilised rapidly timescale measured in months 8

9 ELGIN G4 GAS LEAK: SOLUTIONS TO REGAIN WELL CONTROL 9

ELGIN G4 GAS LEAK: DIVERTER back Specially designed & manufactured Fitted around the leaking G4 well head 4 flexible hoses carry gas & condensates away from the well head

10 ELGIN G4 GAS LEAK: DIVERTER back Specially designed & manufactured Fitted around the leaking G4 well head 4 flexible hoses carry gas & condensates away from the well head Greatly improved frequency of helicopter flights and access to the wellhead Two of the diverter s four flexible hoses G4 well head before diverter fitted and after 10

ELGIN G4 GAS LEAK: POST INCIDENT MILESTONES (1) 29 March: OSRL flights reveal size of sheen has already diminished considerably 30 March: flare is confirmed

UK teams The Sedco 714 drilling rig 15 April: mobilisation of West Phoenix drilling rig & Skandi Aker as main well intervention support vessels 18 April:

11 ELGIN G4 GAS LEAK: POST INCIDENT MILESTONES (1) 29 March: OSRL flights reveal size of sheen has already diminished considerably 30 March: flare is confirmed as extinguished 2 April: pumping in heavy mud & relief well solutions announced 5 April: first re-boarding of Elgin complex by Wild Well Control & Total E&P UK teams The Sedco 714 drilling rig 15 April: mobilisation of West Phoenix drilling rig & Skandi Aker as main well intervention support vessels 18 April: Sedco 714 spuds first relief well 26 April: special diverter fitted to G4 well head Leak rate drops to about 33% of initial rate The diverter on the G4 wellhead 11

ELGIN G4 GAS LEAK: POST INCIDENT MILESTONES (2) April/May: ongoing

temporary rigid pipeline ( chiksan ) 10 May: West Phoenix drilling rig

operation begins The West Phoenix; the main well kill support vessel

12 ELGIN G4 GAS LEAK: POST INCIDENT MILESTONES (2) April/May: ongoing preparatory works successful removal of waxy deposits laying of 230m of temporary rigid pipeline ( chiksan ) 10 May: West Phoenix drilling rig alongside 10/15 May: extensive equipment testing 15 May: well intervention operation begins The West Phoenix; the main well kill support vessel Regular cleaning operations on the Elgin well head platform Chiksan temporary rigid pipeline 12

13 SCANDI AKER Elgin G4 gas leak incident, 25 March 16 May 2012 (June 2012) 13

14 Elgin G4 gas leak incident, 25 March 16 May 2012 (June 2012) 14

15 ELGIN G4 GAS LEAK: WELL INTERVENTION OPERATION Rowan Viking Elgin PUQ West Phoenix Elgin wellhead platform Later following successful operation, the logistics resources deployed 15

16 Elgin G4 gas leak incident, 25 March 16 May 2012 (June 2012) 16

17 ELGIN G4 GAS LEAK: WELL INTERVENTION SET-UP Pre-intervention testing, using flexible hose Coflex from West Phoenix to Elgin PUQ 17

18 ELGIN G4 GAS LEAK: WELL INTERVENTION OPERATION Dynamic well kill with 2.05sg mud Initially pumped water based mud (WBM) Pumped through G4 wellhead into tubing 511m 3 a rate of 10-4bbls/min Pumped via Coflex & chiksan from West Phoenix Pumping for 12 hours No diversion: pumped fluids exited to sea After 3 days, WBM replaced with NABM (Non Aqueous Based Mud) G4 now stable and under observation = mud path while pumping 18

19 ELGIN G4 GAS LEAK: CURRENT STATUS The well has been killed and is filled with oil based mud The well & gas leak path are under control Progressive re-manning of the Elgin complex & the Rowan Viking is underway The West Phoenix was demobilised once the Rowan Viking s pumps were made available As a contingency, drilling of a first relief is progressing But a decision taken not to drill a second relief well following the successful well kill Other Elgin/Franklin wells being monitored Tubing & all annuli filled with NAB mud 19

20 THANK YOU FOR LISTENING any questions? 20

(2) Various fire sections enclosed by various classes of fire divisions; (3) Arrangement of fire detectors and manual fire alarm stations;

(2) Various fire sections enclosed by various classes of fire divisions; (3) Arrangement of fire detectors and manual fire alarm stations; (1979) (Rev.1 1990) (Rev.2 1996) (Rev.3 Jan 2012) Safety features.1 Fire protection and extinction.1.1 General Fire protection arrangements and fire extinguishing systems are to be in accordance with the