P-36

INQUIRY COMISSION

FINAL REPORT

June 2001

Inquiry CommissionInquiry Commission

Carlos HELENO Netto Barbosa Coordinator - Drilling Rigs & Logistics

CID Guilherme Valerio Corporate HSE

RONALDO DIAS Roncador Asset

Carlos BARTOLOMEU Bastos Barbosa Petrobras R&D Center

José Antônio de FIGUEIREDO Engineering Services

Luiz Carlos Nery GUARABYRA Corporate Human Resources

Carlos Henrique de Lima Ferreira Internal Commission for Accident Prevention

Pedro Jose BARUSCO Filho Corporate E&P

Prof TIAGO Alberto Piedras Lopes UFRJ/COPPE (Rio de Janeiro Federal University)

Antônio Carlos Ferreira RANGEL Petroleum Workers Union

SCOPE OF WORK:

contributing factors for the accident and loss of stability of the platform

Recommend measures for the elimination/control of these causes and factors

FINAL PRODUCT:

Most probable hypothesis for the events of March 15th

Conclusions and Recommendations

Verification by DNVVerification by DNV

Well experienced in major accidents

Well experienced in offshore deepwater projects– Leading Classification Society– Safety and Risk Management

Not involved in P-36 design or classification

Verification Team:

– Dr Robin Pitblado - Houston SHE Management Systems– Conn Fagan - Houston Deepwater Unit– Gaylen Roberts - Atlanta Management Consulting Unit– Eduardo Mezzalira - Rio de Janeiro Manager Offshore Services Center

The AccidentMarch 15-20 2001

Develop Hypotheses

Test Hypotheses

Sco

pe

of D

NV

Ver

ifica

tion

Sco

pe o

f Acc

iden

t Inq

uiry

Witness Statements Photographs Video Computer Records Documentation

Rejected HypothesesIterate Timeline/Hypotheses

Formal Accident InquiryImmediate CausesBasic CausesRecommendations

Management System Audit

Final Report

Accident timeline development

Data collection

METHODOLOGY METHODOLOGY

HAZOP Stability Analysis

Dispersion Model

Explosion Analysis

Visit Jack Bates

Documentary Analysis

DATA COLLECTIONDATA COLLECTION

MAIN SOURCE OF INFORMATION (P-36) WAS LOST

MATERIAL RECOVERED FROM P-36– Records of Ballast Operations

– Magnetic Files with Records of Fire & Gas and Emergency Shutdown Systems• (from 8h00min - March 14th to 4h42min - March 15th)

INFORMATION STORED IN PETROBRAS DATABASE– Daily Production Reports

– Operational Status Reports

– Anomalous Occurrences Reports

PLATFORM DOCUMENTATION

VIDEO TAPES AND PHOTOGRAPHS

ARTICLES FROM THE MEDIA

64 INTERVIEWS

Photographs and Videos

Normal Operation

After the Accident

After the Sinking

DATA COLLECTIONDATA COLLECTION

Magnetic Files

•Fire & Gas and ESD records•11,800 entries•1,722 records between 1st and 2nd events (17 minutes)

DATA COLLECTIONDATA COLLECTION

Platform Documentation

DATA COLLECTIONDATA COLLECTION

Timeline

Date/Time System Description

ANALYSISANALYSIS

EVENT

First event. Shaking (jolt). Noise reported as falling deck cargo. Probablemechanical rupture of the starboard emergency drain storage tank.

Verification of pressure loss in the fire tank. PS 70001 alarm sounded

PT-70007 pressure in fire ring fell to 7-bar set point, which automaticallystarts thetwo seawater pumps (XA/401 A/B/C/E) as well as two fire pumps (XA/401A/B/CE)placing the platform in a FIREFIGHTING MODE.

OUTLET DAMPER VE-006ST. (exhaustion of starboard aft column) closes. Thecorresponding EXHAUSTER (XA-2658) receives the same stop signal (status ofthis ventilator is not indicated in the F&G and E8D system)

Waste oil pump XB149A (XB1 49AS) indicates no longer functioning

INLET DAMPER VE-002STS (verification of the starboard aft column) closes.Corresponding VENTILATOR (XA-264H) receives the same stop signal (status ofthe ventilator is not indicated in the F&G and E8D system)XB70519B sea water pump electric drawer signal XA/039C (bow /starboard)turning at high speedOUTLET DAMPER DF-5251 – 09 (starboard aft column elevator well) confirmsclosureXS70701 and XS70704 – General Public Alarm A & B is soundedGas is detected on the Main Deck (external area) at the platform bow and airventilation intakes.Gas detectors GS20HCA/HCB (ventilation intake of fire and freshwater pumpstations) operate at very high levels (60% of the LEL), remaining operational untilcutting out. Gas detectors GS52HCA/HCB (ventilation intake of PP-BE column)operate at high level

HAZOP

ANALYSISANALYSIS

FAULT IN RISERDate:Participants of the HAZOPCoordinator of the HAZOP simplified:

1 Description of scenario according to Commission Inquiry

2 Physically possible?If so, how?

3 Necessary contributory factors4 Scenario indicators before the event

(verifiable)5 Defective safety features6 Liberation rate7 Possible ignition source8 Possible damage caused by the event9 Scenario indicators after the event

(verifiable)10 Intervention11 Probability evaluation of the scenario12 Others

Stability Analysis

ANALYSISANALYSIS

Gas Dispersion and Explosion Analysis

Gas concentration in column(Cross Section)

Explosion due to overpressure

ANALYSISANALYSIS

Visit to Jack Bates

Jack Bates was built according to the same Friede & Goldman design

Water pipes and ventilation shafts on the 4th level

ANALYSISANALYSIS

Especially created diagrams

Damaged Zones

ANALYSISANALYSIS

Event Final/Origin Type

* March 15 2001 00:22:54 ALARM/ALARM UNACK_ALMSmoke detector activated, located in the column, elevation 28956 (DE-5400-855-AMK-223)* March 15 2001 00:24:14 NORMA/ALARM ACK_RTN Smoke detector returns to normal*March 15 2001 00:25:33 ALARM/ALARM UNACK_ALMSmoke detector activated again*March 15 2001 00:26:12 NORMAL/ALARM ACK_RTNSmoke detector returns to normal*March 15 2001 00:40:19 ALARM/ALARM UNACK_ALMSmoke detector activated again

Gas detectors sequence

Gas detectors and dampersactivity

Especially created diagrams

ANALYSISANALYSISTITLE: VENTILATION SYSTEM – FIRE ZONE 4

CAUSE AND EFFECT ANALYSIS

Safety Management System AuditANALYSISANALYSIS

FLUTUADOR

COLUNA

MAIN DECK

SECOND DECK

STABILITY BOX

STARBOARD AFT COLUMN

PONTOON

COLUMN

MAIN DECK

SECOND DECK

STABILITY BOX

FAIR LEARD BOX

TANK TOP

SECOND LEVEL

FOURTHLEVEL

THIRD LEVEL

FIFTH LEVEL

SEAWATER PIPE

SECOND DECK

TANK TOP

VENTILATION PIPE

PONTOON

SEAWATER PUMP

FOURTH LEVEL

FIFTH LEVEL

SEAWATER PIPE

MAIN DECK

TANK TOP

EXHAUST SHAFT

THIRD LEVEL

SECOND DECK

VENTILATION SHAFTS

WASTE OIL TANK

FOURTH LEVEL

THIRD LEVEL

TANK TOP

DRAIN STORAGE TANK

SEAWATER PIPE

VENTILATION PIPE

VIDEO