Well Control – DW Step UpSteffen S Kristiansen / Thomas Nilsen, October 2017
2 oktober 2017Classification: Open
© Statoil ASA
Long term competitiveness Organisational capabilitiesSafety and security
2 oktober 20172 Classification: Open © Statoil ASA
Understand trends
2 oktober 20173 Classification: Open © Statoil ASA
2 oktober 20174 Classification: Open © Statoil ASA
TUBING CUT
1
4
5
6
7
3
2
Well control incident
Operation with course of events:
• When connecting Pulling Tool to TH: TH was unlocked and string jumped 5 - 6 m due to HC gas trapped below.
• Seawater in marine riser evacuated to the rig floor.
• Closed Annular Preventer (AP) (6) and Blind Shear Ram (BSR). BSR closed on TH and did not shear string.
• Well filled with gas from reservoir to AP.
• Well killed by bull heading
Reason for events:
• It is assumed that FCV’s (1) unintentionally opened during BOP connector pressure test (4).
• Poppet valves on top of the TH were exposed during connector test, and pressure was transmitted down the control lines, potentially cycling FCV’s to 100% open position.
• Gas from the reservoir migrated into the well and was trapped below TH and shallow set plug in the tubing until the incident occurred.
Location: Block 31/2
Rig type: Semi Submersible
Well type: P&A – Multi lateral well
Date: 15.10.2016
Level 1
TUBING CUT
1
4
5
6
7
3
2
Learn from details
2 oktober 20175 Classification: Open © Statoil ASA
Risk assessment in planning phase
Handling of risks in execution phase
Indication of well control incident
Handling of influx/kick situation
Competence and training
• WCR - identified and measures addressed *• WCR - awareness among all relevant personnel• QC of swab calculations
• WCR – Morning meetings , DOP arenas, Tool Box talks• WCR - always to be reviewed as part of MOC**• Be open to weak signals
• Volume control• Circulate bottoms up if doubt about downhole situation• Listen to other’s opinions• Worst case approach until else is proven
• Updated Kill sheet • Onshore support available on short notice – Emergency team • Clarify Roles and responsibilities
• Well control certification (IWCF) & Well integrity seminars• Periodic exercises (Drills)• Table tops and simulator training • Experience sharing and learning (One pagers/Safety flash)
Stepping up Well Control DW
2 oktober 20176 Classification: Open © Statoil ASA