UNITED STATES DEPARTMENT OF THE INTERIOR
BUREAU OF SAFETY AND ENVIRONMENTAL ENFORCEMENT
GULF OF MEXICO REGION

ACCIDENT INVESTIGATION REPORT

1. OCCURRED
DATE:

18-JAN-2017

TIME: 0400

HOURS

2. OPERATOR:
Fieldwood SD Offshore LLC
REPRESENTATIVE:
TELEPHONE:
CONTRACTOR:
REPRESENTATIVE:
TELEPHONE:
3. OPERATOR/CONTRACTOR REPRESENTATIVE/SUPERVISOR
ON SITE AT TIME OF INCIDENT:

4. LEASE:
AREA:
BLOCK:

G02646
EB
159

5. PLATFORM:
RIG NAME:

X
7. TYPE:

LATITUDE:
LONGITUDE:

EXPLORATION(POE)
DEVELOPMENT/PRODUCTION
(DOCD/POD)

HISTORIC INJURY
REQUIRED EVACUATION
LTA (1-3 days)
LTA (>3 days
RW/JT (1-3 days)
RW/JT (>3 days)
Other Injury

EQUIPMENT FAILURE
X HUMAN ERROR
EXTERNAL DAMAGE
SLIP/TRIP/FALL
WEATHER RELATED
LEAK
UPSET H2O TREATING
OVERBOARD DRILLING FLUID
OTHER
924 FT.

10. DISTANCE FROM SHORE:

11. WIND DIRECTION:
HISTORIC BLOWOUT
SPEED:
UNDERGROUND
SURFACE
12. CURRENT DIRECTION:
DEVERTER
SPEED:
SURFACE EQUIPMENT FAILURE OR PROCEDURES

COLLISION

MMS - FORM 2010
EV2010R

8. CAUSE:

9. WATER DEPTH:

FATALITY
POLLUTION
FIRE
EXPLOSION
LWC

6. OPERATION:
PRODUCTION
DRILLING
WORKOVER
COMPLETION
HELICOPTER
MOTOR VESSEL
PIPELINE SEGMENT NO.
X OTHER
Plug & Abandonment

A

6. ACTIVITY:

STRUCTURAL DAMAGE
CRANE
OTHER LIFTING DEVICE
DAMAGED/DISABLED SAFETY SYS.
INCIDENT >$25K
H2S/15MIN./20PPM
REQUIRED MUSTER
SHUTDOWN FROM GAS RELEASE
X OTHER Casing weld failure

HISTORIC

>$25K

<=$25K

13. SEA STATE:

85

MI.

M.P.H.

M.P.H.
FT.

PAGE: 1 OF 3
22-MAY-2017

 17. INVESTIGATION FINDINGS:
During milling operations on the A-6 well with 3 1/2" drill pipe and 9 5/8" rock bit,
the crew started to see plugging of the bit. Personnel initiated reverse circulation
methods to unplug the bit when a weld "failure" occurred at the connection of the
original 16" casing and a 16" riser that was recently butt-welded onto the original
casing. The 16" riser section had a 16" added sleeve (collar) to allow the
installation of a 16 3/4" 5M Quick Lok wellhead and a 13 5/8" surface BOP stack. An
"All Stop" was initiated and the producing wells were shut in. There were no
injuries or environmental spills.
Due to failed bubble test, the BSEE Lake Jackson District required the Operator to
install a BOP. The approved permit (RPM) contained no stipulations for hot work
(welding). The Operator welded a section of 16" casing to the existing casing, and
then welded a sleeve (collar) encompassing both sections of casing. Upon completion
of welding, the casing was pressure tested, with multiple failures. This process of
welding and testing was completed until the casing was successfully tested to an
internal pressure of 1000 psi.
During the operation, the crew began reverse circulating. After receiving normal
returns, the crew increased the pump rate to increase barrel flow. At some point,
the rock bit packed off, rapidly increasing the pressure in the 16" casing and
causing the casing to burst. Based on interviews, the estimated internal pressure on
the 16" casing exceeded 2000 psi. Photographs of the burst area indicate failures
along the recently welded seams. The burst pressure of the casing prior to the
welding operations was 4300 psi, and the RPM stated the maximum anticipated surface
pressure (MASP) was 1236 psi. There was no indication the pump safety device(s) set
points were adjusted to account for changes due to welding, indicating the hazard
analysis associated with the task was insufficient. The JSA provided to BSEE
investigators did not address the change in pressure, nor did it address mitigation
procedures for "plugged bit."

18. LIST THE PROBABLE CAUSE(S) OF ACCIDENT:
Pump pressure in excess of 2000 pounds per square inch (psi) during reverse
circulation operations, resulting in failure of the 16" casing butt-weld and 16" riser
welded collar.
19. LIST THE CONTRIBUTING CAUSE(S) OF ACCIDENT:
Exceeded Limitations - BOP's and casing were only tested to 1000 psi.
Inadequate Hazard Analysis - Pump safety devices were not adjusted to account for the
decreased burst pressure.
Management of Change - The JSA was not revised to reflect the implemented changes.
20. LIST THE ADDITIONAL INFORMATION:
RPM was submitted and approved to do cold cutting methods only. Hot work was not
approved by BSEE. This was an abandonment operations.

MMS - FORM 2010
EV2010R

PAGE: 2 OF 3
22-MAY-2017

 21. PROPERTY DAMAGED:

NATURE OF DAMAGE:

16" casing and collar

ESTIMATED AMOUNT (TOTAL):

Split 16" casing and collar

$

22. RECOMMENDATIONS TO PREVENT RECURRANCE NARRATIVE:
No recommendations at this time.
23. POSSIBLE OCS VIOLATIONS RELATED TO ACCIDENT: YES
24. SPECIFY VIOLATIONS DIRECTLY OR INDIRECTLY CONTRIBUTING. NARRATIVE:
1. Lessee P&A crew was unaware of the amount of pressure applied to the BOP stack.
2. Lessee failed to initiate a proper hazard analysis.
3. Lessee failed to revise the Job Safety Analysis (JSA) after the first time the
bit became plugged.
4. Lessee utilized hot work practices such as welding instead of the submitted and
approved procedures which called for cold work installation.
25. DATE OF ONSITE INVESTIGATION:
24-JAN-2017
26. ONSITE TEAM MEMBERS:
Perry Brady / Casey Conklin / James
Holmes /

29. ACCIDENT INVESTIGATION
PANEL FORMED:
NO
OCS REPORT:
30. DISTRICT SUPERVISOR:
John McCarroll

APPROVED
DATE:

MMS - FORM 2010
EV2010R

11-MAY-2017

PAGE: 3 OF 3
22-MAY-2017