well control dw step up - petroleumstilsynet - forside 2017/ptil... · well control –dw step up...

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