ocean drilling program technical note 126hydrogen sulfide - high temperature drilling contingency...
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HYDROGEN SULFIDE - HIGH TEMPERATUREDRILLING CONTINGENCY PLAN
OCEAN DRILLING PROGRAMTEXAS A&M UNIVERSITY
Technical Note 16
Steven P. HowardOcean Drilling ProgramTexas A&M University1000 Discovery Drive
College Station, TX 77845-9547
Daniel H. ReudelhuberOcean Drilling ProgramTexas A&M University1000 Discovery Drive
College Station, TX 77845-9547
Philip D. KabinowitzDirector
Timothy J.G. FrancisDeputy Director
Barry W. HardingMgr. Engr. & Drilling tions
June 1991
This publication has been superseded by ODP Technical Note 33: http://www-odp.tamu.edu/publications/tnotes/tn33/INDEX.HTM
Material in this publication may be copied without restraint for library, abstract service,educational or personal purposes; however, republication of any portion requires thewritten consent of the Director, Ocean Drilling Program, Texas A&M UniversityResearch Park, 1000 Discovery Drive, College Station, Texas 77845-9547, as well asappropriate acknowledgement of this source.
Technical Note No. 16First Printing 1991
Distribution
Copies of this publication may be obtained from the Director, Ocean Drilling Program,Texas A&M University Research Park, 1000 Discovery Drive, College Station, Texas77845-9547. In some cases, orders for copies may require a payment for postage andhandling.
DISCLAIMER
This publication was prepared by the Ocean Drilling Program, Texas A&M University,as an account of work performed under the international Ocean Drilling Program, whichis managed by Joint Oceanographic Institutions, Inc., under contract with the NationalScience Foundation. Funding for the program is provided by the following agencies:
Academy of Sciences (U.S.S.R.)Canada/Australia Consortium for the Ocean Drilling ProgramDeutsche Forschungsgemeinschaft (Federal Republic of Germany)Institut Francais du Recherche pour PExploitation de la Mer (France)Ocean Research Institute of the University of Tokyo (Japan)National Science Foundation (United States)Natural Environment Research Council (United Kingdom)European Science Foundation Consortium for the Ocean Drilling Program
(Belgium, Denmark, Finland, Iceland, Italy, Greece, the Netherlands, Norway,Spain, Sweden, Switzerland, and Turkey)
Any opinions, findings, and conclusions or recommendations expressed in this publicationare those of the author(s) and do not necessarily reflect the views of the NationalScience Foundation, the participating agencies, Joint Oceanographic Institutions, Inc.,Texas A&M University, or Texas A&M Research Foundation.
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HYDROGEN SULFIDE-HIGH TEMPERATURE DRILLING CONTINGENCY
PLAN
OCEAN DRILLING PROGRAM
LEG 139 SEDIMENTED RIDGE SCIENTIFIC DRILLING OPERATIONS
RIG CONTRACTOR - UNDERSEAS DRILLING, INC.*
Drillship - SEDCO/BP471
(6/13/91 - REV 7)
* Underseas Drilling, Inc. (UDI) is an affiliate of SEDCO FOREX, a SchlumbergerTechnology Company.
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PREFACE
Attached is the "HYDROGEN SULFIDE-HIGH TEMPERATURE DRILLINGCONTINGENCY PLAN" that will be used for ODP coring and drilling operations onLeg 139. Prior to commencing with operations at the first site on Leg 139, all safetyequipment and measures described shall be in place and operational. The H2STechnicians shall have confirmed that all personnel working in the designatedhazardous areas (rig floor, core receiving deck, core lab and core reefer/s) have readhis/her copy of the contingency plan. Each person will be required to sign a log thatstates that he/she has read and understands the document.
During coring operations on Leg 139, at all sites where there is a H2S hazardas defined by geological considerations and past drilling experience, the proceduresand policies outlined in this contingency plan will be implemented. This documentis not intended to facilitate continued operations for any extended periods of timeunder emergency Conditions I, II, or III. Rather, this plan defines safety equipmentand procedures that must be in place in the event H2S and/or steam flash conditionsare encountered.
Additional information on metallurgical considerations with regard to H2Senvironments is provided in the Leg 139 Engineering and Planning Document. Also,detailed information on steam flash conditions is contained in the Leg 139Engineering and Planning Document. The UDI Drilling Superintendent, ODPOperations Superintendent, Captain, H2S Technicians, ODP Lab Officers andScientists are to read the Engineering and Planning Document in addition to theContingency Plan. The "HYDROGEN SULFIDE-HIGH TEMPERATUREDRILLING CONTINGENCY PLAN" takes precedence over the "LEG 139ENGINEERING AND OPERATIONS PLAN" with regard to safety actions andprocedures.
6/13/91
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TABLE OF CONTENTS
I. INTRODUCTION 1
IL SAFETY EQUIPMENT LIST AND LOCATION 2
A. SAFE BRIEFING AREA 2B. WIND DIRECTION INDICATORS 3C. H2S WARNING SIGNS 3D. H2S DETECTORS AND ALARMS 3E. DRILL PIPE SAFETY VALVE AND FLOAT VALVE 6F. H2S SCAVENGERS 7G. WORK-CYLINDER RECHARGE STATIONS 7H. CASCADE AIR BREATHING SYSTEM 7I. SELF-CONTAINED BREATHING APPARATUS 8J. EMERGENCY AIR ESCAPE PACKS 8K. LIST OF SAFETY EQUIPMENT 8L. VENTILATION EQUIPMENT 9
III. NORMAL OPERATING PROCEDURES 9
IV. OPERATING CONDITIONS - CLASSIFICATIONS 13
V. H2S EMERGENCY PROCEDURES 13
A. CONDITION I 13
B. CONDITIONS II AND III 15
VI. SPECIAL OPERATIONS 17
A. CORING 17
B. DOWNHOLE MEASUREMENTS 20
VII. HIGH TEMPERATURE WELL CONTROL PROCEDURES 21
VIII. HOLE ABANDONMENT AND MOVING OFF LOCATION 24
IX. RESPONSIBILITIES AND DUTIES 25
A. ALL PERSONNEL 25B. ODP OPERATIONS SUPERINTENDENT 26C. UDI DRILLING SUPERINTENDENT 26D. UDI CAPTAIN 27E. UDI DRILLER 28F. (H2S SAFETY TECHNICIANS) 28G. UDI PHYSICIAN 29
X. PROCEDURE FOR INFORMING PERSONNEL OF THE H2SCONTINGENCY PLAN 29
XI. APPENDIX 31
APPENDIX
I. SAFETY CONSIDERATIONS 33
IL CORE HANDLING PROCEDURES 39
III. TOXICITY OF VARIOUS GASES 48
IV. MUD TREATMENT PROCEDURES FOR H2S CONTAMINATION 51
V. EMERGENCY CONTACT TELEPHONE NUMBERS 52
VI. DRAWINGS 55
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HYDROGEN SULFIDE-HIGH TEMPERATURE DRILLING CONTINGENCY PLANOCEAN DRILLING PROGRAM
LEG 139 SEDIMENTED RIDGE SCIENTIFIC DRILLING OPERATIONSRIG CONTRACTOR - UNDERSEAS DRILLING, INC.
DRILLSHIP - SEDCO/BP471(6/13/91 - REV 7)
I. INTRODUCTION
This plan defines the precautionary measures, safetyequipment, emergency procedures, responsibilities, and dutiespertaining to drilling/coring operations aboard theSEDCO/BP471. Specifically, safety measures and actions aredefined for the rig floor, core walk, core lab, core storagearea, and living quarters with regard to hydrogen sulfide(H2S) and high downhole temperatures that may be encounteredduring operations on Leg 139. This document describesprocedures for handling the core barrels on the rig floor,removing and handling the cores on the core receiving deck andprocessing the cores in the core lab. H2S detection equipmentis described and the location in each area is defined. Thetype, quantity and location of the breathing-air equipment isdescribed. Contained in this document are the definitions ofthe occupational exposure limits, scales, initial response toH2S and toxicity limit values as defined by the Canadianoccupational health and safety legislation and the AmericanNational Standards Institute (ANSI).
The plan also defines special operational procedures thatwill be required for working in both high temperature and H2Senvironments. Methods of circulation during routine coringoperations are specified to maximize hole cooling duringwireline and other special downhole operations. Situationswhen H2S and CO2 scavengers and inhibitors should be mixed withthe drilling fluid are also included. The drill string safetyvalve and its operation are also described.
It should be noted that drilling and coring operationsconducted aboard the SEDCO/BP 471 by the OCEAN DRILLINGPROGRAM are not conventional. Drilling and coring are donewithout a marine riser (no return circulation), drilling forthe most part is done with seawater rather than mud systems,and there is no blowout prevention system.
ODP does not intend to operate for any extended period oftime under Emergency Conditions I, II or III as defined inSection V. Rather this plan defines safety equipment andemergency procedures that must be ready in the event H2Sand/or steam flash conditions are encountered. Thecontingency plan is intended to be used as a means torecognize, recover from and eliminate potentially dangerous
situations. Drilling and coring operations are to besuspended during Emergency Conditions I, II and III and maynot be resumed until the source of H2S has been identified andeither suppressed or dissipated below 10 PPM (parts permillion).
The concentration levels can be minimized by allowing theH2S to diffuse out of the split cores outside the core lab ina well-ventilated area and providing forced ventilation in theareas where H2S is present.
II. SAFETY EQUIPMENT LIST AND LOCATION
Before commencing with drilling and coring operations onLeg 139, the procedures set forth and equipment described inthis document shall be in place and operational.
A. SAFE BRIEFING AREA
The safe briefing areas will be the port andstarboard life boat stations located forward on thefocfsle deck. The location of the designated safebriefing area will be posted by the Captain orMates next to the ship s station bills. The portand starboard life boat stations have beendesignated as the safe briefing areas because whenthe drillship is in the "dynamic positioning mode,"the bow of the ship is nearly always oriented intothe prevailing wind. However, if for some reasonthe stern of the ship was oriented into the wind,the Captain would notify all ship personnel thatthe safe briefing area would be the heliport.Note; the designated safe briefing area will beposted on the station bills by the Captain. Signswill also be posted at the location of thedesignated safe briefing area. The signs willclearly identify the area as the designated safebriefing area. Drawings of the ship showing thosedesignated areas are included in the Appendix. Inthe event an excess of 10 PPM of H?S is detected atone of "the fixed H;S sensors", the ship's Captainor the Mate on duty will determine the appropriatecourse of action and the alarm state/condition thatapplies. The location and emergency state(Conditions I, II, and III described later inSection IV) will be broadcast using coded bellsignals and verbally over the ship s public addresssystem. It is important that the location of theH2S source be broadcast so that personnel can avoidthe H2S danger area as they make their way to thesafe briefing areas. All personnel aft of the rigfloor not assigned emergency duties shall proceedforward to the safe briefing stations along themezzanine or main deck on the windward side of theship. Personnel aft must avoid entering areas
designated as potential H2S danger areas as theyproceed forward to the safe briefing areas. Note:rig floor activity, weather and sea conditions willdictate the best routes to be taken to the safebriefing area from each particular location on theship. The routes will be decided by the Captainand reviewed in safety meetings held with personnelworking in each area of the ship.
B. WIND DIRECTION INDICATORS
Windsocks and streamers (bright colored) will beinstalled on the derrick, bow and stern, positionedas to be seen from any location above the maindeck. See drawing SK 9002.
C. H2S WARNING SIGNS
The following warning shall be posted at theentrance/s of the potential H2S areas when operatingat sites where H2S may be encountered:
WARNING HAZARDOUS AREAHYDROGEN SULFIDE H2S
UNAUTHORIZED PERSONNEL KEEP OUTNO SMOKING
Specifically, warning signs are to be posted in thefollowing areas:
1. RIG FLOOR2. CORE RECEIVING PLATFORM3. CORE LAB - in all areas where cores will be
processed.4. CORE STORAGE REEFER - including reefer
entrance/s.5. BOTTOM OF CORE LAB STAIRWELL - H2S gas may
accumulate in this area.6. LIVING QUARTERS EXITS THAT ARE ENTRANCES INTO
DESIGNATED H2S DANGER AREAS - all deck levels.
D. H2S DETECTORS AND ALARMS
FIXED SENSORS
A fixed continuous "wireless" multi-point gasmonitoring system having sensors located on the rigfloor, core lab, core receiving deck and corereefer storage area/s will be installed. Thedetector system to be used is manufactured inCanada by BW Technologies. TOTCO is providingfield service for the system. The detector unitshave two sensors that can be placed strategicallyin each of the hazardous areas. Each detector unithas a transmitter that sends a signal back to themain alarm panel. The detector units have an alarm
response of less than 8 seconds. This is based onan alarm setting of 10 PPM and exposure to 20 PPMof H
2S gas. A central alarm panel for all sensors
will be installed on the bridge. Warning lightsand horn units will be installed in each of thedesignated hazardous working areas (rig floor, corelab, core reefer areas). A local audible andvisual alarm will sound in the hazardous area whereH
2S is detected. That is, if H
2S is detected on the
rig floor, an audible alarm and warning light willflash on the rig floor. At the same time, anaudible and visual alarm will be triggered on thecentral alarm panel. The Captain will thendetermine the appropriate course of action andwhich alarm state/condition applies. For detailedoperating instructions and specifications, see theTOTCO/BW factory manual. See drawing SK 9004 forthe location of the gas monitoring systemequipment. Note: All fixed H
2S sensors will be set
to alarm at 10 PPM.
FIXED SENSORS - RIG FLOOR/CORE WALK
A fixed continuous multi-point gas monitoringsystem (wireless), capable of sensing a minimum of10 PPM in air, will be mounted in the vicinity ofthe rig floor. The remote sensors are to bestrategically placed on the rig floor and corereceiving platform. See drawing SK 9004. Anysensor can activate the alarm. The sensors will belocated as follows:
1. Riα Floor - A sensor will be placed in thevicinity of the drawworks on line with wellcenter or attached to the iron roughneck. Asecond sensor shall be placed on the forwardside of the rig floor where the core barrel isbroken out and the cores are pulled from thecore barrel.
2. Core Receiving Platform - Two sensors will bemounted in the area where the core is cut into1.5 meter long sections on the core receivingdeck.
FIXED SENSORS - CORE LAB AREA
A fixed continuous multi-point gas monitoringsystem (wireless) shall be installed in the corelab. See drawing SK 9004. Sensors are to beinstalled in the following locations:
1. Core Storage Rack - A sensor shall be mountedin the vicinity of the core storage rack.Core sections 1.5 meters long are stored on
this rack prior to splitting. A secondary rackwill be located outside the lab stack on thecore receiving platform for storage of wholecores.
2. Core Splitting Room - A sensor is required inthis area because this is where the cores areinitially split and exposed to the atmosphere.Until that time the 1.5 meter core sectionsare in sealed plastic liner sections.
3. Core Processing Area - Two sensors will beplaced in the description and core samplingareas. One will be placed adjacent to thestorage of "working" halves and the secondbetween the core photo and description table.
FIXED SENSORS - CORE REEFER STORAGE AREA/S
A fixed continuous multi-point gas monitoringsystem (wireless) shall be mounted in the corereefer located on the lower 'tween deck used forstoring the cores (those that contain H2S). Onesensor will be mounted inside the reefer and asecond sensor will be mounted in the lower 'tweenlanding just outside the core storage door. Seedrawing SK 9004.
Note: cores containing significant levels of H2Swill be stored in a separate reefer containerlocated above deck. One sensor will be mountedinside the container and a second sensor will bemounted just outside the container door. If allthe H2S cores are stored in the above deck reefercontainer, the sensors in the lab reefer located onthe lower 'tween deck may not be needed.
Additional sensors will be located in the labstairwell. A fixed, continuous, multi-point gasmonitoring system shall be mounted in the hold decklanding. This system will have two sensorsconnected to a single alarm monitor. One will bemounted inside the forward hold storage area andthe second at the bottom of the stairwell.Emergency air escape packs (3 ea) will be locatedinside the elevator. Consideration should be givento disabling the ability on the elevator control toselect the lowermost two decks in the lab stackfrom inside the elevator car. (The ODP and UDISuperintendents are to decide on the best way tohandle this situation.)
Fixed sensors will also be located in the livingquarters fresh air intake vent and the core labfresh intake vent.
PORTABLE PERSONAL MONITORS
In addition to the fixed sensor systems describedabove, portable personal monitors will be placed instrategic locations in the hazardous areas asfollows.
1. Core Splitting Room - A portable personalmonitor will be placed in the core splittingroom. The portable monitor will be used forchecking for localized gas concentrationsaround groups of freshly split core sections.
2. Core Processing Area - Two portable personalmonitors will be placed in the main lab areaswhere the cores are initially handled. Thosemonitors can be moved to the areas (differentlab stack levels as required) where cores arebeing processed.
3. Rig floor - Two portable personal monitorswill be placed on the rig floor for takinglocalized readings when the drill string isopened and when core catchers are broken out.One of those detectors will be carried by thederrickman at all times when working in thepump room.
4. Core Receiving Platform - A portable personalmonitor will be placed on the core receivingplatform for taking localized readings whenthe core is cut into 1.5 meter long sections.
5. Reefer Area - A portable monitor will beplaced next to the reefer fixed monitor unitlocated in the stairwell. That monitor is tobe carried by personnel when entering thereefer and in areas such as the forward holdor stores area.
E. DRILL PIPE SAFETY VALVE AND FLOAT VALVE
A safety valve (ODP part number OG 0785) with5-1/2" internal flush (I F.) box and pinconnections is kept on the rig floor. The safetyvalve has a 3.9" throughbore. The valve isintended to be used as an in-line blowout preventer(BOP) in the event of excessive backflow of fluidthrough the drill string. If excessive backflowdoes occur, the valve is to be installed in thedrill string. Once the valve is in place and
closed, a second sub containing a float valveassembly can be made up on top of the safety valve.The Baker model G (5F-6R) float valve acts as acheck valve allowing fluid to be pumped down thedrill string but prevents fluids contaminated withH2S or hot fluids from backflowing up the drillstring. The float valve is to be used for specialoperations only. If the float valve is installed,some downhole tools cannot be run. Both the drillpipe safety valve and the float valve must betrimmed for H2S service.
F. H2S SCAVENGERS
Drilling fluid additives (H2S and C02 scavengers)will be carried on board to help reduce downholeconcentrations of H2S and C02 that may enter thewellbore. Since returns are not brought back tothe surface, it is not practical or economical tocontinuously pump the scavengers or inhibitors. Asufficient volume of H2S scavenger shall be on boardto allow slugs to be pumped when not circulatingfor long periods of time and between cores ifrequired.
G. WORK-CYLINDER RECHARGE STATION
The work-cylinder recharge station for rechargingthe portable air breathing cylinders will belocated on the bridge deck roof behind the DPControl Room.
H. CASCADE AIR BREATHING SYSTEM
A cascade air breathing system will be installed onthe rig floor, core receiving deck, inside the corelab and in the alternate core splitting area ifused. Refer to drawings SK 9002 and SK 9050 forthe location and detailed layout of the equipmentthat will be placed in each area. The cascadebreathing system will allow breathing equipment tobe worn for long periods of time. The air maskunits will have a 50-foot hose that connects in thecascade air supply. Each air mask unit will alsohave a self-contained 5-minute air supply. If itbecomes necessary to evacuate the area, the 50-foothose can be disconnected from the mask. The self-contained 5-minute air supply is turned on and usedto move to a safe area.
The cascade stations designated C1, C2 and C3 aresupplied with air from an air compressor located on
the bridge deck roof. See the cascade systemoperating manual for details of the operation andmaintenance of all the cascade system components.
I. SELF-CONTAINED BREATHING APPARATUS (SCBA).-
Self-contained breathing units (30-minute) will beplaced in the following locations:
1. Rig Floor - SCBA units (6 ea) for the rig crewwill be stored in a readily accessiblelocation on the rig floor. The storagelocation/s shall be away from the immediatewell center where the H2S is likely to beemitted.
2. Core Lab - SCBA units (4 ea) for personnelassigned with emergency duties shall be placedin this area. There will be 2 ea SCBA unitson the core receiving deck.
3. Safe Briefing Area - SCBA units (6 ea) shallbe placed and maintained in safe briefingareas. Those air packs will be assigned topersonnel with emergency duties such as rescueof personnel in hazardous areas.
4. Reefer - SCBA units (2 ea) shall be placed inthe vicinity of the reefer in the stairwell onthe lower tween deck.
EMERGENCY AIR ESCAPE PACKS
Three (3) emergency air escape packs shall belocated inside the lab stack elevator. The escapepacks provide a 5-minute emergency supply of air.
K. LIST OF SAFETY EQUIPMENT
The location and quantity of all safety equipment(including respirators, resuscitators, H2Sdetectors, etc.) will be maintained on a separate"Safety Equipment Inventory" by the designated H2SSafety Technicians. Also a location layout drawingis provided in this section for reference.
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L. VENTILATION EQUIPMENT
One electric fan (bug blower) with an explosionproof motor will be installed on the rig floor andone will be installed on the core receiving deck.The bug blowers are to be directed aft/downwind.Two portable smoke ejector fans will be placed inthe lab stack. The fans will be used to ventilateareas where concentrations of H2S have been detectedin areas such as the core splitting room, main lab,etc.
In addition to the fans, positive pressure normallywill be maintained in the lab stack. That willhelp to force air out of the exits when it isnecessary to use the portable smoke exhaust fans inlocalized areas in the lab stack. Note: the labstack ventilating system is separate from theliving quarters system. Scrubber fan units will belocated in the core lab in the vicinity of coredescription tables to help control the level of H2Sin the lab.
III. NORMAL OPERATING PROCEDURES
A. PRIOR TO COMMENCING WITH OPERATIONS AT LEG 139SITES
1. The list of phone numbers of shorebasedpersonnel to be contacted concerning H2Semergencies is included in Appendix V. A copyof the list will be posted in the followinglocations:
a. ODP Operations Superintendent's officeb. UDI Drilling Superintendent s officec. UDI Captain s officed. ODP Lab Officer s officee. UDI radio room
2. All safety equipment and H2S-related hardwaremust be set up as outlined on the locationlayout drawings contained in the Appendix.All safety equipment must be routinelyinspected, paying particular attention tobreathing apparatus and recharge stations.
3. All personnel assigned to emergency dutieswill be assigned self contained breathingapparatus and notified as to where thebreathing apparatus is stored. ODP and UDI
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personnel assigned to emergency duty in thefollowing areas will be provided withbreathing-air equipment:
a. Rig Floorb. Core Receiving Platformc. Core Labd. Reefere. Rescue Team in Safe Briefing Area
4. All personnel aboard the drillship, withoutexception, shall be notified of the potentialdangers of H2S, and to a lesser extent, C02,radon and hydrocarbon gases. All personnelwithout exception shall watch the UDI H2S videotraining module. All personnel (UDI Crew, ODPOperations Personnel, Scientists, LDGO and LabTechs) working in the designated hazardousareas (rig floor, core walk, core lab, andcore reefer) must complete a H2S safety coursetaught by a qualified H2S instructor. Thecourse will include thorough training in theuse of breathing equipment, emergencyprocedures, responsibilities and first aid forH2S victims.
The H2S Safety Technicians must keep a list ofall personnel who have completed the specialtraining programs aboard the vessel. Allpersonnel (UDI Crew, ODP Operations Personnel,Scientists and Lab Techs) working in or aroundthe designated hazardous areas shall be givena copy of the H2S contingency plan and a copyof "The Hydrogen Sulfide Technical Manual".The H2S Technician must keep a list of allpersons that have copies of the plan andsignatures verifying they have read andunderstand the contingency plan and technicalmanual thoroughly.
B. ON SITE OPERATIONS
1. The H2S detection equipment will be maintainedby designated H2S Safety Technicians. Thedetector/sensor units will be calibratedduring the initial installation. As per themanufacturer s recommendation, no additionalcalibration is required for 90 days unlessthere is a specific problem with one of theunits. During the first week of operation,the detector/sensor units are to be tested 3
10
times on different days. Both sensors on eachof the units are to be tested. The detectorsshould be tested more frequently if problemswith any specific detector unit occurs. Afterthe first week of operation the detector unitsare to be tested once a week. The time oftests and results will be logged by the H2SSafety Technicians.
In the event that a H2S detector or sensor onthe rig floor does not test successfully,drilling will cease until the defective itemis (1) repaired/replaced, and (2) approval toproceed is given by the UDI DrillingSuperintendent. Spare sensors and a sparedetector will be available on board.
2. Blowout drills will be held as often as deemednecessary by the UDI and ODP OperationsSuperintendents to acquaint the crews andservice personnel with their responsibilitiesand the proper way to secure the drill pipesafety valve.
3. All personnel aboard the vessel will beinstructed in the use of breathing-airequipment until supervisory personnel aresatisfied that they are capable of using theequipment.
4. After familiarization, personnel working inthe designated hazardous areas must perform aweekly drill with the breathing-air equipment.The drill should include getting theequipment, putting it on, and a short workperiod. A record should be kept of the crewsdrilled and the date.
Blowout drills which incorporate the use ofthe breathing equipment with the installationof the drill pipe safety valve will beconducted until the supervisory personnel aresatisfied that rig floor personnel are capableof using the equipment effectively.
5. Along with the normal weekly fire and boatdrill and safety meeting, a weekly breathing-air equipment demonstration and H2S training
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session must be held for all personnel thatwere not required to complete the in-depth H2Ssafety course.
6. Rig Crews, Scientists and Lab Techs shall bemade aware of the location of the spare airbottles, the resuscitation equipment, portablefire extinguishers and H2S detectors.Knowledge of the location of H2S detectionsensors is vital to understanding theemergency conditions. Key personnel must betrained in the use of the resuscitator and H2Spersonal monitors.
7. The H2S portable personal monitors areavailable for working personnel as needed.After H2S is detected by any fixed sensor,periodic inspections of all areas of poorventilation (such as bottom or lab stairwelland forward hold area, etc.) shall be madewith a portable H2S personal monitor.
8. All personnel on the ship must become "wind-conscious" and be aware at all times of thedirection of the prevailing winds. Remember,H2s is heavier than air and will collect in lowplaces when the air is still.
9. In the event H2S is detected at the surface, nowelding shall take place until the surroundingair is thoroughly tested with an explosimeter.A hot work permit shall be required for allwelding in the designated hazardous at alltimes whether gas has been detected or not.(H2S has a low ignition point of 500 degrees Fand is explosive when mixed with air inconcentrations between 4.3 and 46 percent.)
10. After drilling into an H2S zone, increasedmonitoring of the working areas will beprovided during coring operations, specialdownhole measurement operations, logging andrunning of subsea hardware. If the H2S levelreaches 10 PPM at a fixed H2S sensor,protective breathing apparatus must be worn byall working personnel.
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IV. OPERATING CONDITIONS - CLASSIFICATIONS
Drilling and coring operations may occur under fourpossible conditions.
A. NORMAL OPERATIONS - H2S NOT PRESENT
H2S ALERT - WHEN H2S LEVELS BELOW 10 PPM AREINITIALLY DETECTED THE CAPTAIN WILLANNOUNCE THAT A H2S ALERT CONDITIONEXISTS FROM THE POINT IN THEHOLE/CORES WHERE MINUTE AMOUNTS OFH2S ARE ENCOUNTERED.
B. CONDITION I - POTENTIAL DANGER TO LIFE - H2S PRESENTAT 10 TO 20 PPM.
C. CONDITION II - MODERATE DANGER TO LIFE - H2S PRESENTAT 20 TO LESS THAN 50 PPM.
D. CONDITION III - EXTREME DANGER TO LIFE - H2S PRESENTAT 50 PPM OR GREATER.
A detailed description of operating conditions isincluded in the Appendix.
V. H2S EMERGENCY PROCEDURES
Note: drilling and coring operations will not be conducted ifan Emergency Condition I, II or III exists on the rig floor,core walk or core lab. The Emergency Condition must bebrought under control before drilling operations proceed.
A. EMERGENCY PROCEDURE FOR CONDITION I
If, at any time, as much as 10 PPM of H2S is detected bya fixed H2S sensor, the following steps are to be taken:
1. The person detecting the H2S must immediately notifythe Captain or Mate on watch as to the area (rigfloor, core receiving platform, core lab, etc.)where the gas was detected. The Captain or Matewill then decide on the appropriate course ofaction and if a Condition I emergency status iswarranted. The bridge will then notify theDriller, ODP Operations Superintendent and UDIDrilling Superintendent of the action required.
The following personnel will immediately put ontheir breathing-air equipment.
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a. All personnel assigned to emergency duties inthe area/s where the Condition I emergencyexists (rig floor, core receiving platform,core lab and reefer).
b. All personnel that are required (for emergencyor other vital reasons) to work below anddownwind of the source of H2S.
The H2S Safety Technician/s on duty will bringportable H2S detectors to the area where the H2S wasdetected to find the source.
2. Upon notification by the bridge of a Condition Iemergency occurrence on the rig floor, corereceiving platform, or core lab, the Driller willmake the string backup (if open) , pick up offbottom and maintain circulation.
3. The Captain will alert all personnel that aCondition I exists. All personnel not assigned toemergency duties must get their lifejacket/survival suits and report to the upwind safebriefing area for further instructions. The Captainwill be prepared to shut down ventilation systemsand to close all hatches downwind and below thesource of H2S.
4. Supervisory personnel shall make the maximum effortto determine the source of the H2S and to suppressthe H2S as quickly as possible. Drilling/coringoperations must not proceed until the source of H2sis located and suppressed to a level below 10 PPM.Note: depending on the source of the H2S, the holemay be terminated as determined by the ODP and UDIDrilling Superintendents. The hole could also beterminated for H2S concentrations being too high inthe core lab as well as on the rig floor. Ifconcentrations of H?S in the cores produce EmergencyConditions I. II. or III in the core lab, this ispotentially a more dangerous situation than on therig floor due to the confined space and reducedventilation.
5. The UDI Drilling Superintendent will ensure thatall nonessential personnel are out of the potentialdanger area (rig floor, core receiving platform,and core lab areas). All persons who remain in thepotential danger area must utilize the "buddysystem" (see Appendix).
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6. The Captain or Mate will ask all personnel to checktheir safety equipment to confirm that it isworking properly and stored in the proper location.
7. The on-duty Safety Technicians will confirm thatall H2S monitoring devices are functioning properly,reading accurately, and will increase gasmonitoring activities with portable detectionunits.
8. Depending on the location of the Condition Iemergency the fans on the rig floor or in the corelab should be turned on if not already inoperation. Note: if the exhaust fans in the labstack are turned on to exhaust H2S the Driller is tobe notified because the exhaust fans exhaust airabove the rig floor.
9. The ODP Operations Superintendent shall notify theCanadian National Energy Board as soon as possibleof the situation and the actions taken (seeAppendix V for contacts).
B. EMERGENCY PROCEDURES FOR CONDITIONS II AND III
If the H2S concentration reaches 20 PPM at a fixed sensorthe following steps will be taken.
1. The person detecting the H2S must immediately notifythe Captain/Mate on watch of the area (rig floor,core receiving platform, core lab, etc.) where thegas was detected. The Captain or Mate will thendecide on the appropriate course of action and if aCondition II or III emergency status is warranted.The bridge will then notify the Driller, ODPSuperintendent and UDI Drilling Superintendent ofthe action required as directed by the Captain orMate.
The following personnel will immediately put ontheir breathing-air equipment.
a. All personnel assigned to emergency duties inthe area where the Condition II or IIIemergency exists (rig floor, core receivingplatform, core lab, and reefer).
b. All personnel required (for emergency or othervital reasons) to work below and downwind ofthe source of H2S.
15
The H2S Safety Technician on duty will bringportable H2S detectors to the area where the H2S wasdetected to find the source.
2. Upon notification by the Captain or Mate ofCondition II or III emergency, the driller willmake the string back up (if open), pick up offbottom and maintain circulation.
3. The Captain will alert all personnel that aCondition II or III exists. All personnel notassigned to emergency duties must get their lifejacket/survival suits and report to the upwind safebriefing area for further instructions. TheCaptain will have one member of the ship s crewprepared to shut off ventilation systems and closeall hatches downwind of the H2S source.
4. Always put on a portable breathing air unit beforeproceeding to assist anyone affected by the gas andutilize the "Buddy System" (see Appendix). If theaffected person is stricken in a high concentrationarea, put on a safety belt with 50' of tail lineand obtain stand-by assistance before entering thearea. Always use the "buddy system" when enteringpossible contaminated areas.
5. The Captain or Mate on duty shall notify any nearbyvessels to go upwind, and maintain a radio andvisual watch.
6. Supervising personnel shall make a maximum effortto determine the source of the H2S and to suppressthe H2S as quickly as possible. Drilling/coringoperations will not proceed until the source of H2Sis located and suppressed. Note: depending on thesource of the H2S the hole may be terminated asdetermined by the UDI Drilling Superintendent. Thehole may be terminated for H2S concentrations beingtoo high in the core lab as well as on the rigfloor. If concentrations of H7S in the coresproduce Emergency Conditions I, II. or III in thecore lab this is potentially a more dangeroussituation than on the rig floor due to the confinedspace and reduced ventilation (see Appendix II - H?SCore Handling Procedures).
7. The UDI Drilling Superintendent will make sure thatall nonessential personnel are out of the potentialdanger area (rig floor, core receiving platform,
16
and core lab areas). All persons who remain in thepotential danger area must utilize the "buddysystem.
M
8. The ODP Superintendent will ask all personnel tocheck their safety equipment to confirm that it isworking properly and stored in the proper location.
9. The on-duty Safety Technicians will confirm thatall H
2S monitoring devices are functioning properly,
reading accurately, and will increase gasmonitoring activities with portable detectionunits.
10. The ODP Operations Superintendent will notify theCanadian National Energy Board as soon as possibleof the situation and actions taken (see Appendix Vfor contacts).
The UDI Drilling Superintendent, in consultation with theODP Superintendent, will assess the situation and assignduties to each person to bring the situation under control.When the severity of the situation has been determined, allpersons on the vessel will be advised. λs stated above,depending on the location of the H
2S Condition II or III
emergency, the UDI Drilling Superintendent may elect toimmediately terminate drilling and coring operations in thehole.
In the event the concentration of H?S present results in
injury to personnel the designated shorebased medical facilityshall be contacted. If it is deemed necessary bv the shipdoctor to evacuate the person/s, arrangements shall be madewith the designated helicopter service. In the event anevacuation and/or H
?S/wellbore fluid blowout occurs, the
National Energy Board is to be notified bv the ODP OperationsSuperintendent. The Captain or Mate on duty shall notify airand water craft in the immediate vicinity of the drillinglocation.
VI. SPECIAL OPERATIONS
A. CORING
During coring operations where it is likely that H2S gas
will be encountered, the following procedure shall befollowed:
1. Circulation will be maintained while a corebarrel is dropped or wirelined into and out ofthe hole.
17
2. After a core has been cut, circulation will bemaintained while running the wireline assemblyinto the hole for retrieval of the corebarrel.
3. After the overshot has been engaged on top ofthe core barrel, it may be necessary to stopthe pumps momentarily while unseating the corebarrel from the outer core barrel assembly.The core barrel should be slowly pulled upabove the top of the bottom hole assembly(BHA). The wireline winch should be stoppedat this point and three volumes (number ofbbls.) of fluid (equal to the volume requiredtofill the inside of the BHA) should be pumpedto clear any H2S fluid that may have beenswabbed in the BHA when the core barrel wasunseated.
4. As the core barrel is wirelined to thesurface, circulation down the drill stringwill be maintained. Wireline speeds are to becontrolled such as to prevent/minimizeswabbing H2S fluids into the drill string fromthe wellbore.
5. At the point in the hole where H2S is detected(1 PPM or more) all personnel working on therig floor are to put on breathing-airequipment 10 stands before each core barrelreaches the surface. This procedure will befollowed until H2S is no longer viewed as athreat in each hole where the gas isencountered. When the drill pipe is initiallyopened, one of the rig crew shall use apersonal monitor to check for the presence ofH2S gas in the drill pipe.
Note: The pipe must be confirmed not tocontain H2S prior to sending one of the rigcrew up in the derrick to remove the sinkerbars from the blocks and to close the WKMvalve.
If H2S is detected, breathing-air equipmentshould be worn by all personnel working in thearea while the core barrel is being pulledfrom the drill string, laid down, broken outand removed. Portable personal monitorsshould be used to monitor for H2S when thedrill string is 1) opened prior to removing
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the core barrel from the drill string and 2)after the core barrel is laid down and thecore catcher is removed. When those detectorsindicate a safe atmosphere, the breathing-airequipment can be removed.
The following practices must be followed for every corebarrel pulled:
1. Due to the difficulty in communicating whilewearing breathing-air equipment, it isrequired that a chalk board/chalk and notepads be available during coring operations.
2. The importance of wearing breathing-airequipment must be stressed to personnelconnected with the coring operations. Themost critical times are:
(1) When the drill string is initially openedto remove the core barrel on the rigfloor. (If H2S was swabbed in the drillpipe as the core barrel was retrieved, aconcentration of the gas could possiblyexist at the surface below and around thecore barrel.)
and
(2) When the core barrel is opened. H2S maybe contained in the core inside the corebarrel.
3. All personnel on board not wearing breathing-air equipment should stay a safe distanceupwind from the core barrel as defined by theCaptain or Mate.
4. If the core contains H2S, the 1.5 meter longcore sections are to be marked indicating thepresence of H2S.
5. If the core contains H2S, the liner/"D" tubesare to be marked as such. The core will bestored on the core receiving deck and theliner will be perforated. Note: specifichandling procedures for processing corescontaining H2S are contained in the Appendix.
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B. DOWNHOLE MEASUREMENTS, SAMPLING AND LOGGING
As with coring operations, special precautions must betaken when running downhole measurement, sampling andlogging tools in areas where H2S gas may be encountered.The procedures below shall be followed:
1*. Circulation is to be maintained while runningwireline tools in and out of the hole. Care shallbe taken to ensure that excessive flow rates,sufficient to pump the wireline tools off thewireline, are not used. This has happened in thepast with logging tools.
2. After the measurements or sampling has beencompleted and the wireline tool/s have beenretrieved inside the BHA, the sampling or measuringtool is to be stopped above the top of the BHA.Three volumes (number of bbls) of fluid (equal tothe volume of fluid required to fill the inside ofthe BHA) are to be pumped to clear any H2S fluidthat may have been swabbed into the BHA when thetool was pulled inside the BHA.
3. As the wireline tool/s are retrieved to thesurface, circulation down the drill string is to bemaintained. Wireline speeds are to be controlledsuch as to prevent swabbing H2S fluids into thedrill string from the wellbore.
4. After H2S has been detected (1 PPM or more) allpersonnel working on the rig floor are to put onbreathing-air equipment 10 stands before themeasuring/sampling tool reaches the surface.
Breathing-air equipment should be worn by allpersonnel in the area while the measuring/samplingtool is being pulled from the drill string, laiddown, broken out and removed. Portable personalmonitors should be used to monitor for H2S aroundthe measuring/sampling tool. When the detectorsindicate a safe atmosphere, the breathing-airequipment may be removed.
Note: prior to sending one of the rig crew up inthe derrick to remove the measuring/sampling toolsfrom the blocks and to close the WKM valve, thepipe must be confirmed not to contain H2S.
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5. When water sampling tools and pressure core barrelsare run, extreme caution must be used in handlingthe sample chambers containing the wellbore fluids.Prior to deployment, each tool is to be carefullyinspected to determine if it is suitable forcollecting water samples that may contain H2S. Ifthere is any question as to whether a tool issuitable for use in a H2s environment, do not runthe tool.
Upon retrieval of a sampler containing fluids froma zone suspected to contain H2S, the sample chamberis to be marked "possible presence of H2S". Thefluid contained within the sample chamber will beassumed to contain H2S until actual measurements aremade on the fluid that indicate otherwise.
In addition to the possible presence of H2S in thewellbore, C02 and corrosive brine solutions may alsobe present. The wellbore fluids may have pH levelsas low as 2 to 4. These fluids are highlycorrosive. Components that are not designed foroperation in H2S and C02 environments aresusceptible to sulfide and stress corrosioncracking. The cracking may occur downhole or atthe surface over relatively short periods of time.
In the event fluids containing corrosives arestored in the sample chamber for even short periodsof time, a failure may occur if the chamber is notmade of the proper material.
Special precautions and extreme caution are to beobserved when storing as well as when handlingsample chambers with H,S fluids under pressure.
VII. HIGH-TEMPERATURE WELL CONTROL PROCEDURES
In the unlikely event a steam flash occurs, the firstindication at the surface would be backflowing of seawater atthe rig floor when making-up or breaking-out a connection (orthe Cavins wireline packoff in the derrick if pulling a corebarrel). Because of the water depth, steam may never reachthe surface but hot water containing H2S could reach thesurface if the backflow continued at the surface for a longenough period of time. (See the Leg 139 ODP Engineering andOperations Planning Document for additional information.)
1. If excessive backflow is observed at the rig floorfor a significant length of time and H2S is not
21
present, the top drive should be immediately madeback up to the drill string. In the event the topdrive is stood back, the drill pipe safety valve isto be immediately installed. This will control thebackflow while the top drive is being picked up.
2. If H2S is detected when the backflow occurs,emergency procedures as defined in Condition I, IIor III are to be implemented immediately. The rigcrew should first put on breathing-air equipment,then install the safety valve.
Blowout drills which incorporate the use of thebreathing equipment with the installation of thedrill pipe safety valve will be conducted until thesupervisory personnel are satisfied that rig floorpersonnel are capable of using the equipmenteffectively.
In the event it is necessary to use the drill pipe safetyvalve, the following procedure will be followed. The drillpipe safety valve is installed in the open position. Once thevalve is made up, it can be closed, bringing the backflow ofseawater under control. Note: short-term bacXflowing at therig floor is normal and can be caused by cuttings and/orweighted mud "U tubing11 in the hole. Under normal conditions,when backflowing occurs due to "U tubing" of cuttings, the topdrive kelly joint is made back up to the drill string hung offat the rig floor. Regardless of the cause of backflow. makingthe top drive kelly back up to the drill string is still thepreferred method for controlling backflow.
If it is necessary to use the safety valve, a second"optional" sub containing a Baker model G (5f-6R) float valvecan be made up to the safety valve after the safety valve isin place and is closed. The float valve acts as check valveallowing fluid to be pumped down the drill string butpreventing backflow of fluid up the drill string. If thevalve is put into the string and the pipe is run down thehole, there is a high risk of sticking the drill string.Chances of getting loose downhole are reduced to nil ifcirculation is plugged off (too hot for explosives).
The top drive or the circulating head can be made up tothe safety valve and/or float valve subs. At that point,circulation down the drill string can be re-established byopening the safety valve and pumping. Depending on the bottomhole temperatures and hole conditions, it may be possible tocool the hole back to manageable levels (as is done in thegeothermal industry). Depending on the severity of thebackflow and the circumstances that caused the backflow, theUDI Drilling Superintendent may elect to terminate the hole.
22
If H2S is detected in the backflowing fluid, the hole is to beterminated immediately.
As stated above, short-term backflowing at the rig flooris normal and can be caused by cuttings and/or weighted mud"U-tubingM in the hole. Once the backflow has been broughtunder control and the hole stabilized, the ODP and UDIDrilling Superintendents may elect to continue operations inthe hole. If, after the hole has been stabilized, backflowingcontinues to occur and high temperatures are present downhole,the hole should be terminated due to the possibility of asteam flash. Note: depending on the bottom-hole temperature,pumping of muds (weighted or otherwise) may result in pluggingof the bit jets and core barrel circulation ports.
If the hole is terminated due to continued/excessivebackflow problems, it may be necessary to cool the hole downseveral times while tripping the pipe out of the hole. Timeshould be minimized for breaking out and laying outconnections. Between connections, it may be necessary tocirculate at high flow rates to prevent additional backflowfrom occurring. Times of greatest risk for a steamflash/backflowing occurrence are during operations thatprevent or minimize circulation such as when makingconnections, wirelining core barrels in and out of the hole,logging, and taking downhole measurements/samples.Considerable caution and discretion must be used whenundertaking such operations in sections of the hole wherebottom hole temperatures are high.
To minimize possible steam flash problems and to preventswabbing in of corrosive wellbore fluids, special precautionsmust be taken. When running the wireline retrieval system inthe hole and when pulling core barrels, circulation at lowflow rates (50 GPM or higher) shall be maintained. When thecore barrel is initially unseated and clears the top of theBHA, the wireline is to be stopped momentarily. During thistime three volumes of drilling fluid (equal to the volumerequired to fill the inside of the BHA) are to be pumped toclear out any corrosive wellbore fluids that may have beenswabbed into the BHA when the core barrel was initiallyunseated. Note: depending on bottom hole temperatures* thereis a possibility of "high temperature" gelation of mud. Thiscould plug the bit if circulation is stopped for any reasonbefore the mud clears the bit. If bottom hole temperatureswarrant, seawater or a high-temperature mud system (ifavailable) should be used instead of a conventional mudsystem. Circulation will be continued while the core barrelis wirelined out of the hole. The time required for breakingthe drill string and removing/replacing the core barrelsshould be minimized.
23
There is no real-time method available to monitordownhole temperatures or H2S levels. It is planned to monitortemperatures by use of heat tabs and temp-stick materialstrategically placed on the core barrels. That will give anindication of the operating temperatures in the BHA. Levelsof H2S being emitted from the cores will be measured with theportable personal monitors. Levels of H2S contained withinthe cores will be measured by one of two means, either in gasor fluid samples taken from the core. See memorandum titledMH2S Detection on the JOIDES Resolution" written by Dr. MartaVon Breymann in the "Engineering and Planning Document".
VIII. HOLE ABANDONMENT AND MOVING OFF LOCATION
In the unlikely event that uncontrollable or excessivebackflow occurs, the following action will be taken by UDI:
1. Make the top drive back up to the string. If thetop drive is set back, the safety and float valvescan be used to arrest the flow while the top driveis being picked up. Once the top drive has beenpicked up, circulation will be initiated andmaintained in order to cool the hole and hopefullystop the backflow. If this is ineffective, thepipe will be slugged with heavy mud. Once the holeis staticr the pipe will be tripped out in doubles.
2. In the event the pipe becomes irretrievably stuck,there are drill pipe severing and back-off tools onboard that can be run inside the drill pipe on thelogging cable. The severing tools carry anexplosive charge that is capable of cutting thedrill string above the stuck point. The severingtools have a maximum temperature above which theelectronics and/or logging cable will not function.There is also a maximum safe drilling fluid surfacetemperature for handling the charges on the rigfloor, above which the explosives could detonateprematurely. The Schlumberger operator shalldetermine the temperatures and advise the UDIDrilling Superintendent.
As long as there is no backflow and circulation canbe maintained, the drill pipe can be severed orbacked off in the conventional manner.
* If backflow is occurring, the proceduresdescribed in Section VII are to be used to cool thehole and to stop the backflow prior to running thesevering tool or back-off tool.
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3. If it is not possible to perform either actiondescribed in 1 and 2 above, the pipe should betripped in the hole until it parts at the seafloor.This has unintentionally been demonstrated to workin the past.
If breaking the pipe at the seafloor is notpossible, a blind back-off with the top driveshould be attempted.
If that procedure fails, the drill string maypossibly be released from the elevators using atugger/s to open the elevator doors. Note: if H?Sis present in sufficient concentration inside thedrill pipe at the surface, an explosion will resultif a torch is used to cut the pipe free.
As a last resort after attempting the aboveprocedure the following may be considered;
If none of the other procedures worked, thendriving the ship off location may be attempted ifconditions are extreme. This action may result inpulling the pipe free at the sea floor or the pipeparting at the surface. This action is extremelydangerous. All personnel should be clear of therig floor and the drill pipe should be hung off inthe elevators on the rig floor with the linksdisconnected.
IX. RESPONSIBILITIES AND DUTIES
As stated in Special Provision No. 17 (pg. 11-13) of theUDI/TAMRF Subcontract, it is UDI S "sole and exclusive duty atall times" to determine whether operations can be continued orundertaken, therefore the responsibilities outlined below arenot intended to circumvent the contract terms but are merelyto assist in or prevent an emergency situation. In any event,all final decisions shall be UDI S.
A. All Personnel
1. It is the responsibility of all personnel workingin the designated hazardous areas (rig floor, corewalk, core lab and reefer) to familiarizethemselves with the procedures outlined in thisContingency Plan.
2. Each individual is responsible for his/her assignedsafety equipment and is to see that it is properlystored and easily accessible.
25
3. Each person assigned to emergency duties in thedesignated hazardous areas must be familiar withthe location of all safety equipment aboard thevessel and be able to use all safety equipment uponnotice.
4. All personnel working in the hazardous areas mustread and understand the information in the articletitled "SAFETY CONSIDERATIONS WHILE OPERATING INAREAS WHERE HYDROGEN SULFIDE MAY BE PRESENT"contained in the Appendix.
5. Any person detecting H2S must notify the Captain orMate as to the area (rig floor, core receivingplatform, core lab, etc.) where the gas wasdetected. The Captain or Mate will notify theDriller, ODP Superintendent, UDI DrillingSuperintendent.
B. ODP OPERATIONS SUPERINTENDENT
1. The ODP Superintendent shall be trained and willassist the UDI Drilling Superintendent in enforcingthe "HYDROGEN SULFIDE—HIGH TEMPERATURE DRILLINGCONTINGENCY PLAN."
2. The ODP Superintendent will assist the UDI DrillingSuperintendent in seeing that all safety andemergency procedures outlined in the contingencyplan are observed by the personnel aboard thedrillship.
3. The ODP Operations Superintendent will assist theUDI Drilling Superintendent in seeing that allpersonnel are trained as specified under SectionIII, "NORMAL OPERATING PROCEDURES".
4. The ODP Operations Superintendent will ensure thatthe ODP H2S Technicians are maintaining all ODP H2Sand high-temperature safety equipment (H2Sdetectors, breathing equipment, drill string safetyvalve, etc.) on the rig in good operationalcondition.
UDI DRILLING SUPERINTENDENT
It is the responsibility of the UDI DrillingSuperintendent to thoroughly understand and, alongwith the assistance of the ODP OperationsSuperintendent, to see that all safety and
26
emergency procedures outlined in this "HYDROGENSULFIDE—HIGH TEMPERATURE DRILLING CONTINGENCYPLAN" are observed by all personnel aboard thedrillship.
2. The UDI Drilling Superintendent shares theresponsibility with the assistance of the ODPOperations Superintendent to ensure that allpersonnel aboard the ship have been trained asspecified under Section III, "NORMAL OPERATINGPROCEDURES."
3. The UDI Drilling Superintendent, with theassistance of the ODP Superintendent, isresponsible for seeing that all H2S and High-Temperature Safety Equipment (H2S detectors,breathing equipment, drill string safety valve,etc.) on the rig are maintained in good operationalcondition.
4. The UDI Drilling Superintendent or UDI RigSuperintendent shall notify the Captain or Mate onduty of all H2S emergencies.
D. UDI CAPTAIN
1. When H2S is encountered, the Captain or Mate on dutyis solely responsible for determining what actionis required, and as necessary, sounding the generalalarm to notify personnel to report to thedesignated safe briefing area.
2. The Captain or Mate on duty is solely responsiblefor designating the safe briefing area. This areawill change depending on the wind direction.Another safe assembly area may be designated if theoriginally designated briefing (2 ea) areas arefound to be unsafe for some reason.
3. The Captain or Mate on duty is responsible forkeeping all personnel advised of the current safebriefing area.
4. The Captain or Mate on duty is responsible foralerting all personnel during a Condition I, II, orIII alert.
5. The Captain or Mate on duty is responsible fornotifying vessels and aircraft in the area of H2Semergencies.
27
6. A ship s officer will always be present on thebridge once an "alert" condition has been reported.
E. UDI DRILLER
1. The driller and his crew must be completelyfamiliar with the steps they must take during aCondition I, II or III emergency as outlined underSection V, "H2S EMERGENCY PROCEDURES".
2. The driller and his crew must be completelyfamiliar with special procedures to be carried outwhile coring, and running downholemeasurement/sampling and logging tools as outlinedin Section VI, "SPECIAL OPERATIONS".
3. The driller and his crew must be completelyfamiliar with special procedures for high-temperature well control outlined in Section VII,"HIGH-TEMPERATURE WELL CONTROL PROCEDURES".
4. The Driller shall be familiar with hole abandonmentprocedures outlined in Section VIII, "HOLEABANDONMENT AND MOVING OFF LOCATION".
F. H2S SAFETY TECHNICIANS
Designated members of the UDI Deck Department (Mates) andthe ODP Lab Officers/Techs will be assigned duties as H2STechnicians.
1. The H2S Safety Technicians are responsible forinspecting all continuous monitoring H2S sensors.
2. The H2S Technicians are responsible for thecalibration of the H2S monitors and alarm system(fixed and personal type).
3. The H2S Technicians are responsible for inspectingand maintaining all breathing-air equipment. Alist showing all breathing-air equipment and itslocation will be checked weekly.
4. The H2S Technicians are responsible for thefamiliarization of all personnel on the vessel withthe "HYDROGEN SULFIDE-HIGH TEMPERATURE DRILLINGCONTINGENCY PLAN" as directed by the UDI and/or ODPSuperintendents.
28
5. The H2S Technicians are responsible for thefamiliarization of all new personnel arriving onthe vessel with the "HYDROGEN SULFIDE—HIGHTEMPERATURE DRILLING CONTINGENCY PLAN" and thepresent condition under which the vessel isoperating.
6. The H2S Technicians are responsible for assistingthe ODP and UDI Drilling Superintendents as neededduring H2S drills and Emergency Conditions I, II andIII.
7. The H2S Technicians shall confirm that all personnelworking in the designated hazardous areas havecompleted all required safety training courses.
8. The H2S Technicians shall confirm that the H2Swarning signs are posted in the locations asspecified in Section II (C) "H2S WARNING SIGNS".
G. UDI PHYSICIAN
As is normal procedure, the Physician shall confirm thatall leg participants have completed the requiredphysical. In addition to the standard requirements,personnel working in the hazardous areas must be examinedto confirm that they do not have a punctured ear drum.Even if personnel are wearing breathing equipment, HoScan enter the body through a punctured ear drum.
The Physician will be responsible for ensuring that theship is stocked with any special medical supplies thatmay be needed for treating personnel exposed to H2S. ThePhysician will also assist with training in resuscitationand H2S first aid procedures.
X. PROCEDURE FOR INFORMING PERSONNEL OF THE H2S CONTINGENCYPLAN
Prior to commencing operations, the H2S Technicians shallhave confirmed that all personnel working in the designatedhazardous areas (rig floor, core receiving platform, core laband reefer) have read his/her copy of the "HYDROGEN SULFIDEDRILLING CONTINGENCY PLAN". Each person will be required tosign a log that he/she has read and understands the plan. If,during the leg, additional personnel come onto the vessel, itis the H2S Technicians
1 responsibility to ensure that the newpersonnel are given and have read their copy of theContingency Plan.
29
X I . APPENDIX
APPENDIX I
SAFETY CONSIDERATIONS WHILE OPERATING IN AREAS WHEREHYDROGEN SULFIDE MAY BE PRESENT
This document is intended to familiarize personnel withconditions that can exist when drilling/coring operations areconducted in areas where H2S gas may be present.
All personnel should become familiar with all safetyequipment on the vessel, its use, and its location. Thewindsock and wind streamers are provided to show whichdirection the wind is blowing so that the "SAFE BRIEFING AREA"can easily be defined. Personnel should become "windconscious" and observe the wind direction indicators. Allpersons aboard the SEDCO/BP 471 will receive instructions onthe use of safety equipment and on what to do during a H2Semergency. The designated hazardous areas (rig floor, corereceiving platform, core lab and core reefer/s) will bemonitored by fixed continuous H2S detectors. Portablepersonal monitors will also be placed in all of the designatedhazardous areas.
The following conditions will be in effect duringdrilling and coring at sites where H2S is anticipated to beencountered. Once H?S has been encountered in an area, theCaptain or Mate will decide if Condition I. II. or III iswarranted.
A. NORMAL OPERATIONS - H2S NOT PRESENT AND H2S ALERT
1. WARNING SIGNS - Warning signs will be posted andmaintained at all times in all designated hazardousareas as defined in Section II C of the "HYDROGENSULFIDE-HIGH TEMPERATURE CONTINGENCY PLAN."
2. ALARM - None
3. CHARACTERIZED BY - Drilling and coring operationsbeing conducted at sites that may contain hydrogensulfide. This condition will be in effectcontinuously at all sites unless it is necessary togo to a Condition I, II or III.
4. GENERAL ACTION
a. Be alert for a changing condition.b. Keep all safety equipment available and
sensors functioning properly.c. Perform all drills for familiarization and
proficiency.
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B. CONDITION I - POTENTIAL DANGER TO LIFE - H2S PRESENTAT 10 TO LESS THAN 20 PPM
1. WARNING SIGNS - Warning signs will be postedand maintained at all times in all designatedhazardous areas as defined in Section II C ofthe "HYDROGEN SULFIDE-HIGH TEMPERATURECONTINGENCY PLAN".
2. ALARM - In the hazardous area (rig floor/corereceiving platform, core lab and reefer/s)where H2S is detected at a fixed sensor inconcentrations of 10 PPM or greater, aflashing strobe light will come on. Indesignated areas (rig floor, core lab, andreefer/s) a siren will also sound. The alarms(flashing light and siren) will be local onlyfor the area where H2S is detected. At thesame time, an alarm will be triggered on thecentral alarm panel. The alarm signal willcontinue as long as the H2S concentration is 10PPM or greater in the area or untildeactivated by the H2S Technicians, ODPOperations Superintendent, or UDI DrillingSuperintendent.
3. CHARACTERIZED BY: - Drilling and coringoperations halted until the source of H2S islocated and suppressed. This condition willbe in effect continuously from the time the H2Sconcentration reaches 10 PPM unless it isnecessary to go to Condition II or III.
4. GENERAL ACTION
a. Follow the procedures outlined underSection V, "H2S EMERGENCY PROCEDURES".All personnel not assigned to emergencyduty shall report to the safe briefingarea.
b. There will be "No Smoking" outside ofliving quarters. Welding or open firesare not allowed in the hazardous areas atany time without a hot work permit.
c. Check all safety equipment for properlocation and functioning. Keep itavailable.
d. Follow the instructions of theSupervisor/s.
34
All personnel working in the hazardousarea will wear self contained breathingequipment. All personnel will restricttheir movements as directed by the UDIand ODP Operations Superintendents.
C. CONDITION II - MODERATE DANGER TO LIFE - H2S PRESENT AT2*0 TO LESS THAN 50 PPM
1. WARNING SIGNS - Warning signs will be posted andmaintained at all times in all designated hazardousareas as defined in Section II C of the "HYDROGENSULFIDE-HIGH TEMPERATURE CONTINGENCY PLAN".
2. ALARM - In the hazardous area (rig floor/core R/P,core lab and reefer/s) where H2S is detected at afixed sensor in concentrations of 10 PPM or greatera red flashing light will appear. In designatedareas (rig floor, core lab, and reefer/s) a sirenwill also sound. The alarms (flashing light andsiren) will be local for only the area where H2S isdetected. At the same time an alarm will betriggered on the central alarm panel. The alarmsignal will continue until as long as the H2Sconcentration present is 10 PPM or greater in thearea or until deactivated by the H2S Technicians,ODP Operations Superintendent, or UDI DrillingSuperintendent.
3. CHARACTERIZED BY: - Drilling and coring operationshalted until the source of H2S is located andsuppressed. This condition will be in effectcontinuously from the time the H2S reaches 20 PPM toless than 50 PPM unless it is necessary to go toCondition III.
4. GENERAL ACTION
a. Follow the procedures outlined under SectionV, "H2S EMERGENCY PROCEDURES". All personnelnot assigned to emergency duty shall report tothe safe briefing area.
b. There will be no smoking outside of livingquarters. Welding or open fires are notallowed in the hazardous areas at any timewithout a hot work permit.
c. Check all safety equipment for proper locationand functioning. Keep it available.
35
Follow the instructions of the Supervisor/s.
All personnel working in the hazardous areawill wear self-contained breathing equipment.All personnel will restrict movements asdirected by the UDI and ODP Superintendents.
D. CONDITION III - EXTREME DANGER TO LIFE - H2S PRESENT AT50 PPM OR GREATER
1. WARNING SIGN - Follow the procedures outlined underSection V, "H2S EMERGENCY PROCEDURES". Allpersonnel not assigned to emergency duty shallreport to the safe briefing area.
2. ALARM - In the hazardous area (rig floor/core R/P,core lab and reefer/s) where H2S is detected inconcentrations of 10 PPM or greater a red flashinglight will appear. In designated areas (rig floor,core lab, and reefer/s) a siren will also sound.The alarms (flashing light and siren) will be localfor only the area where H2S is detected. At thesame time an alarm will be triggered on the centralalarm panel. The central panel alarm will continueuntil deactivated by personnel on the vessel'sbridge.
3. CHARACTERIZED BY - Drilling and coring operationshalted until the source of H2S is located andsuppressed. This condition will be in effectcontinuously from the time the H2S reaches 50 PPM orgreater.
4. GENERAL ACTION
a. Follow the procedures outlined under SectionV, "H2S EMERGENCY PROCEDURES". All personnelnot assigned emergency duties shall report tothe SAFE BRIEFING AREA. Radio communicationsshall be used to alert known air and watercraft in the immediate vicinity. Notificationof regulatory agencies will be made.
b. All personnel not specifically assigned tocorrect or control the emergency shall stay inthe SAFE BRIEFING AREA until the situation isbrought under control. If the situationbecomes life threatening to personnel in thesafe briefing areas, at the UDI DrillingSuperintendents discretion, non-essentialpersonnel are to be evacuated off the ship in
36
the life boats as necessary. A suggestedlist of essential personnel to be left onboard will be prepared by UDI.
c. There will be no smoking outside of livingquarters. Welding or open fires are notallowed in the hazardous areas at any timewithout a hot work permit.
d. Check all safety equipment for proper locationand functioning. Keep it available.
e. Follow the instructions of the Supervisor/s.
f. All personnel working in the hazardous areawill wear self contained breathing equipment.All personnel will restrict movements asdirected by the UDI and ODP Superintendents.
E. GENERAL INFORMATION ON H2S SAFETY
1. During an emergency, persons should utilize the"buddy system" to prevent anyone from entering anH
2S area alone. If you are wearing a mask, do not
remove it until you are absolutely certain the airis safe to breathe. A personal H
2S monitor can be
used to check the area. If a sudden gas releaseoccurs without warning, you should:
a. Hold your breath and rapidly evacuate the areacontaining the H
2S. Move upwind if possible.
Climb up the derrick or move up a floor orclimb atop the lab stack.
b. Put on breathing-air equipment.
c. Help anyone who may be affected by the gas.NOTE: Put on vour breathinσ-air equipmentbefore helping anyone overcome bv H
2S. Then
get him/her to a safe area and administerresuscitation or oxygen as needed.
d. Evacuate quickly to the "SAFE BRIEFING AREA"to receive instructions from supervisorypersonnel.
e. Do not panic.
2. All personnel, including the Captain and Matesworking in the designated hazardous areas, shallbecome familiar with the "HYDROGEN SULFIDE-HIGHTEMPERATURE CONTINGENCY PLAN". Particularattention should be paid to the following topics:
37
a. H2S EMERGENCY PROCEDURESb. RESPONSIBILITIES AND DUTIESc. SAFETY EQUIPMENT LIST AND LOCATION
3. Personnel wearing eyeglasses and contact lensesmust take special precautions when wearingbreathing equipment. The ear pieces on theeyeglasses will interfere with the seal on theface mask of both the self contained breathingapparatus and the cascade breathing system. Lensholders will be provided to mount eyeglasses insidethe face masks with the ear pieces removed.
Injuries have been sustained by personnel wearingcontact lenses using breathing-air equipment. Thepositive pressure in the face mask can push thelens up inside the cavity of the eye. The positiveair pressure also dries the eye out behind the eye.Therefore, contact lenses should not be worn withthe breathing equipment face masks. Instead, apair of conventional glasses should be worn insidethe face mask using the lens holder as describedabove.
The tables on the following pages list variouspoisonous gases and the concentrations at whichthey become dangerous.
F. MEDEVAC
We have established contact with Pacific Rim Helicopter,based at Vancouver International Airport. They have confirmedthat they can provide a helicopter (Bell 222, equipped foroffshore operation) on an as needed basis to transfer apatient from the ship to shore, weather permitting.
38
APPENDIX II
H?S CORE HANDLING PROCEDURES
1.0 OBJECTIVE:
The objective of this document is to provide procedures forthe safe handling of H2S-rich cores by technicians andscientists. These procedures will cover core handling in thecore receiving, core lab and core storage areas.
These procedures are probably extremely conservative. It isexpected that the Operations Superintendent, Lab Officer, andH2S Safety Technician will re-evaluate these proceduresthroughout the cruise. Some modification of these proceduresmay be necessary.
2.0 CORE HANDLING
2.1 From the rig floor to the core receiving platform
During an H2S Alert (defined in the H2S Contingency Plan) , itwill be assumed that each core can produce hazardous levels ofH2S. Until testing indicates otherwise, personnel on the rigfloor are required to use a personal protective breathingapparatus. Procedures for handling cores on the rig floor arecovered in the H2S Contingency Plan.
When a core arrives on deck:
1) Non-essential personnel will not be allowed on therig floor or on the core receiving platform.
2) Core handlers without protective breathingapparatus must remain upwind from the rig floor andoutside the ship s hazardous zone. The hazardouszone is the area within a 50-ft. radius of the well(see the SEDCO/BP 471 Marine Operation's Manual formore detailed description). For Leg 139 theboundary of this zone will be marked on the corereceiving platform.
When the core is ready to be transferred to the receivingplatform:
1) Core handlers must use their protective breathingapparatus.
All safety precautions must remain in effect until both:
1) Accumulated free gases inside the liner havevented.
39
2) H2S levels in the core receiving area are below 10ppm.
The core lab H2S safety technician will notify personnel whenprecautions are no longer necessary.
2.2 On the core receiving platform
2.2.1 Gas shows:
As soon as the core is laid out on the core racks, it must beinspected for gas shows (ie. foamy sediment, bubbles andexpansion voids). If gas is evident, then:
1) The core lab H2S safety technician insures that:
a) Non-essential personnel are not on the corereceiving platform and remain indoors untilthe "all clear" is given.
b) Core handlers are using personal protectivebreathing apparatus.
2) Take gas samples (vacutainer) for lab analysis(science data).
3) Perforate the core liner as necessary to relieveaccumulated free gases.
4) Measure H2S levels of escaping gas with a portableair monitor. If portable air monitors detect H2Slevels greater than 10 ppm then:
a) Immediately notify the mate-on-watch of thesituation.
b) Check fixed air monitors. If H2S levels aregreater than 10 ppm, then relocate the core toa "safe area" for degassing (see 5.0 fordefinition of a safe area).
Note: For both opaque plastic and metal (split and continuous)liners, the presence of free gas will always be assumed andthe above degassing procedures must be performed.
-Opaque plastic liners: perforated at least every 50 cmfor degassing and testing.
-Split metal liners: remove the top half of the liner fordegassing. Monitor escaping gases with a portable airmonitor.
40
-Continuous metal liners: core material must be extrudedinto pre-split plastic liners. During the extrusionprocess, all safety precautions must be in use. Monitorescaping gases with a portable air monitor.
The core lab H2S safety technician will give the "all clear"when both of the following conditions exist:
1) There are no gas shows or all accumulated freegases inside the liner have vented.
2) Both portable and fixed air monitors indicate H2Slevels less than 10 ppm.
2.2.2 H2S/LAB Test:
The H2S/LAB test will determine the amount of H2S in the core.This will be performed on the Interstitial Water sample (IW).The IW is taken immediately after accumulated free gasesinside the liner have been vented. Pore waters are squeezedfrom the sediment and the concentration of H2S is determinedby standard laboratory methods.
This test will be performed on all cores during Leg 139,whether or not the Contingency Plan is in effect. The H2Ssafety technician and shipboard geochemists will decide whereand how many samples to take. If gas shows are not present,samples can be taken without special precautions. Otherwise,the precautions used for gas shows must be continued untilaccumulated free gases in the liner have vented, and bothportable and fixed monitors indicate H2S levels less than 10ppm.
The H2S/LAB test results are compared to two threshold levelsfor H2S in the interstitial waters. These levels aredesignated as the Lab Threshold (LT) and Storage Threshold(ST) . The determination of the LT and ST values arediscussed in section 4.0.
Cores that have H2S levels above the LT:
1) Cannot be taken inside the lab spaces.
2) Are to have H2S warning stickers affixed to liners.
3) Must be degassed until their H2S levels are belowthe LT.
4) Must be repeat tested until H2S levels are below theLT.
41
Most core degassing can be accomplished by perforating thecore liner. Cores with very high levels of H2S can be splitin half to expose more surface area. A portable core splitterwill be provided to split cores outside the core lab.
Cores that have H2S levels above the ST and below the LT:
1) Are to have H2S warning stickers affixed to liners.
Cores with H2S levels below the ST can be processed and storedas usual.
2.3 Inside the Core Lab
There are no specific H2S tests performed inside the core lab.Harmful cores are identified by the H2S/LAB test and preventedfrom entering the lab. Personnel should remain alert,however, to the possible buildup of H2S inside the core lab.It is important that the following tasks/precautions beperformed:
1) Monitor H2S levels near the Core Entry s core rack.
2) Monitor H2S levels in the Core Splitting roomwhenever a core is split (especially those coresmarked with H2S warning stickers).
3) Make sure that cores with H2S levels above the SThave H2S warning stickers affixed to both archiveand working half liners, D-tubes and core boxes.
4) Do not split a new core until the previous core isstored in its D-tube. All cores are to be sealedin the tri-laminated foil before being stored inthe D-tubes. Cores will be sealed as quickly aspossible to reduce H2S fumes inside the lab spaces.
5) Ensure that bench top H2S scrubbers are functioningproperly.
6) Ensure that the lab stack's air conditioning andexhaust systems are balanced and functioningproperly
7) In the event that the lab levels of H2S detected atany sensor exceed 10 ppm: All personnel are to beevacuated and the H2S safety technicians will removeall unsealed cores from the core lab. The fanswill be used to vent the lab and personnel will notreenter the lab until H2S levels are below 10 ppm.
42
2.4 Storage
As previously mentioned, cores with H2S levels above the STare stored outside the lab stack. Cores with H2S levels belowthe ST can be stored in the ship•s core storage area as longas these are sealed in the tri-laminated foil before being putin the D-tubes. Although an H2S scrubber system will beinstalled inside the ship s core storage space and in the"outside" storage area, personnel entering these spaces shouldbe cautious and must always:
1) Check the air monitor for hazardous H2S levels.
2) Work with a partner. Never enter alone!
3) Carry a portable air monitor on his/her personwhile inside the storage area.
3.0 CORE LAB H2S SAFETY TECHNICIAN JOB DESCRIPTION
The core lab H2S safety technician is a member of the H2SSafety squad (see the H2S Contingency Plan for additionalinformation). During an H2S Watch condition, he/she must bepresent on the core receiving platform as each core isrecovered and will be responsible for the following tasks:
1) Enforcing H2S safety policy on the core receivingplatform and in the core lab.
2) Ensuring that all H2S testing is completed andconducted in a safe manner.
3) Recording the results of all tests for each core.
4) Ensuring that cores with H2S levels above the SThave H2S warning stickers affixed to their liners,D-tubes and core boxes, for both archive andworking halves.
5) Ensuring that personnel handling hazardous coresare using their personal protective breathingapparatus correctly.
6) Ensuring that safety equipment is in good conditionand functioning properly.
7) Ensuring that monitoring equipment is calibratedand functioning properly.
43
8) Being responsible for notifying the UDI/ODPDrilling Superintendents when H2S alarm conditionsexist or when H2S levels measured by the H2S/LABtest are above the LT.
9) Testing the pH of each core for acidic fluids. Ifacidic fluids are found, ensure that core handlingpersonnel are wearing protective clothing.
10) Posting warning signs and limiting access tohazardous areas.
4.0 DETERMINATION OF THE LAB & STORAGE THRESHOLD VALUES
4.1 Definitions (also see 2.2.2):
LAB THRESHOLD: The Lab Threshold (LT) is defined as theconcentration of H2S for a given amount of split core(both archive and working halves) that will produce aconcentration of 10 ppm of H2S in the air volume of theCore Splitting room after one hour of exposure.
STORAGE THRESHOLD: The Storage Threshold (ST) is definedas the LT for 950 cm of core recovery. (With 100%recovery, 950 cm is the length of core recovered in onecore barrel.)
4.2 Equations:
Equation 1 is used to calculate the amount of H2S produced bymolecular diffusion for a given concentration, core surfacearea and time.
(1) J(/xg/cm2 sec) * A(cm2) * T(sec) = M(µg)
where: J is the mass flux per unit area with time
A is the area of the split core s surface
T is time of exposure
M is the mass of H2S
The concentration of H2S in the air volume is given by:
(2) CL(/xg/g) M(µg) / [V(cm3) *Pair(g/cm3) ]
orM (fxg)= CL(µg/g) * Pair(g/cm3) * V(cm3)
where: CL is the concentration of H2S in the lab airspace
44
Pair is the density of air
M is the mass of H2S
V is the volume of air
Combine equations 1 and 2:
J(µg/cm2 sec) * A(cm2) * T(sec) - CL(µg/g) * Pair(g/cm3) * V(cm3)
Expand the mass flux term J:
The value J is determined by Fickfs first law (Crank,1975):
J = D CJ X
where: D is the diffusion constant
Cc is the concentration of H2S in the core.This value is determined by the H2S/LAB test.Because the concentration of H2S in the air isassumed zero, then 3cc = Cc
X is the diffusion path. We111 assume that allgases released from the core are homogeneouslymixed in the lab air space. Therefore theterm X = X
Substitute for the J term:
(3) [D(cm2/sec) * Cc(µg/cm3) / X(cm) ] * A(cm2) * T(sec) =
CL(/*g/g) * Pair(g/cm3) * V(cm3)
4.3 Determination of the LT and ST values:
To determine the LT and ST limits we must solve for Cc Thisis done by rearranging equation 3 as follows:
(4) Cc(µg/g) - [<Uµg/g) * Pair(g/cm3> * V(cm3) * X(cm)] /
[D(cm2/sec) A(cm2) * T(sec)]
Before solving equation 4, values for the above terms must bedefined:
CL: 10 µg/cm3 the maximum level of H2S allowed in the Core
Splitting room by definition.
*airs density of air 1.204 ×IO~3 g/cm3
45
V: volume of the air space above Core Splitting table:250 cm x 100 cm x 100 cm = 2.5 x I06 cm3
X: diffusion path from the center of the split core toits surface = 1.6 cm
D: diffusion constant = 10 x I0"6 cm2/sec. H2S in solutionwill be mainly in the species HS- which has an activitycoefficient similar to the Cl- ion. The diffusionconstant for Cl- in a typical fine grained marinesediments ranges from 10 to 20 * I0'6 cm2/sec. Theeffects of tortuosity, temperature, chemical reaction andinter-ion effects are not considered.
A: area of the split core s surface for both archive andworking halves • R(cm) * 6.6 cm , where R is the corerecovery. Because there are two halves this value ismultiplied by 2. Also because the surface is rough, termA must be multiplied by a roughness factor of 5(estimate).
T: 1 hour of exposure = 3.6 x I03 sec (average time toprocess a core after splitting)
Substitute the values for equation 4:
(4) Cc(µg/cm3) = [10 µq/q * 1.204 X I0"3 g/cm3 * 2.5 x I06 cm3
* 1.6 cm] /[1.0 x I0"5 cm2/sec * [R (cm) * 6.6 cm
* 2 * 5] * 3.6 x I03 sec]
Simplify the equation to produce the formula for the Labthreshold value as a function of core recovery. This functionis graphed below.
(5) For LT: Cc(µg/cm3) • 2 x 10* (µg/cm2)/ R (cm)
To determine the ST value set R to 950 cm and solve equation5.
(5) Cc(µg/cm3) = 2 x 10* (µg/cm2)/ 950 (cra)= 21.3 or 20 ppmin the interstitial waters
4.4 Threshold Graph:
By plotting the ppm of H2S vs. core recovery on the followinggraph, the H2S hazard potential for each core can bedetermined.
46
Note: This graph is based on the assumption roughness factorof 5; diffusion constant of 10; exposure of 1 hour, and an LTof 10 ppm. This graph is for illustration purposes only!
500 i
THRESHOLD LIMIT
NOT ALLOVED IN LAB
STORAGE THRESHOLD LIMIT
200 400CORE RECOVERY R (CM)
'STORE OUTSIDE LAB AND MARK
600 S00
PROCESS AS NORMAL
4.6 A Word of Caution:
As you have probably noticed, the values used in the aboveequations for the diffusion constant, roughness factor, etc.,are "guesstimates". As we gain experience handling H2S coreswe may need to revise these estimates. Because of our lack ofexperience of handling H2S cores it is important that the corelab safety procedures outlined in section 2.3 be followed tomaintain a safe working environment inside the core lab.
5.0 SAFE AREA
The "safe area" is an exterior location on the ship wherecores can degas without creating a downwind hazard for otherpersonnel. Because weather will influence the location ofthis area, its selection will be made by the ship•s personneland approved by the UDI/ODP Drilling Superintendents. Anychanges in ship•s heading during an H2S Watch must be approvedby the ODP/UDI Drilling Superintendents. Also, any changes inthe wind direction must be reported to the ODP/UDI DrillingSuperintendents, and corrective action taken immediately.
47
APPENDIX I I I
TOXICITY OF VARIOUS GASES
Common Name Formula
Hydrogen Cyanide HCN
Hydrogen Sulf ide H2S
Sulfur Dioxide SO2
Chlorine CL2
Carbon Monoxide CO
SpecificChemical Gravity Threshold1 Hazardous2
Limit Limit
Carbon Dioxide
Methane
co2
CH4
i ir=i)
0.94
1.18
2.21
2.45
0.97
1.52
0.55
Lethal3
Concentration
10 ppm
10 ppm
2 ppm
1 ppm
50 ppm
5000 ppm
90000 ppm
150 pp•/1 hr
250 ppm/1 hr
4 ppm/1 hr
400 ppm/1 hr
5%
CombustibleAbove 5% in air
300 ppm
600 ppm
1000 ppm
1000 ppm
1000 ppm
10*
^Threshold - concentration at which i t i s believed that a l lworkers may repeatedly be exposed, day after day, withoutadverse effect.
'Hazardous - concentration that may cause death.3Lethal - concentration that wil l cause death with short-ter•exposure.
PROPERTIES OF GASES
The produced gas will probably be a mixture of carbon dioxide,hydrogen sulfide, and methane.
A.Carbon Dioxide
1.Carbon dioxide (C02) is usually considered inert and iscommonly used to extinguish fires. I t is heavier than air(1.5 times), and C02 will concentrate in low areas of quietair . Air containing 5% CO2 will cause disorientation in afew minutes. Continued exposure to CO2 after being affectedwill cause convulsions, coma, and respiratory failure.2.The threshold limit of CO2 is 5,000 ppm. Short-termexposure to 50,000 ppm (5%) is reasonable. This gas iscolorless and odorless and can be tolerated in relativelyhigh concentration.
48
B. Hvdroαen Sulfide
1. Hydrogen sulfide itself is a colorless, transparentgas and is flammable. It is heavier than air andhence, may accumulate in low places.
2. Although the slightest presence of H2S in the air is
normally detectable by its characteristic "rottenegg" odor, it is dangerous to rely on the odor as ameans of detecting excessive concentrations becausethe sense of smell is rapidly lost, allowing lethalconcentrations to accumulate without warning. Thefollowing table indicates the poisonous nature ofHydrogen Sulfide, which is more toxic than CarbonMonoxide.
CONCENTRATION
[H2S PPM (GR/lOCnSCF
EFFECTS
0.001
0.002
0.01
0.02
0.05
0.07
0.1
10
20
100
200
500
0.65
1.30
6.48
12.96
32.96
Obvious and unpleasantodor. Safe for 8 hours.
700
1000
45.36
64.80
Safe forexposure.
hours
Kills smell in 3 to 15minutes; may sting eyesand throat.
Kills smell shortly;stings eyes and throat.
Dizziness; breathingceases in a few minutes;needs prompt artificialrespiration.
Unconscious quickly;death will result if notrescued promptly.
Unconscious at once;followed by death withinminutes.
49
C. Sulfur Dioxide
1. Sulfur dioxide is a colorless, transparent gas andis nonflammable.
2. Sulfur dioxide (S02) is produced during the burningof H2S. Although S02 is heavier than air, it willbe picked up by a breeze and be carried downwind atelevated temperatures. While sulfur dioxide isextremely irritating to the eyes and mucousmembranes of the upper respiratory tract, it hasexceptionally good warning powers in this respect.The following table indicates the toxic nature ofthe gas.
CONCENTRATION EFFECTS
1S02 PPM
.0002 2 Safe for 8 hours.
.0005 3 to 5 Pungent odor - normally a person candetect SO2 in this range.
.0012 12 Throat irritation, coughing,constriction of the chest, tearingand smarting or burning of eyes.
.015 150 So irritating that it can only beendured for a few minutes.
.05 500 Causes a sense of suffocation, evenwith first breath.
50
APPENDIX IV
MUD CHEMICALS PROCEDURES FOR H?S CONTAMINATION
The option of treating the circulating fluid with chemicalshas been considered at some length. Because Sedco-BP 471 isnot equipped with a recirculating mud system, any treatmentchemical would be circulated through the hole quickly andlost. Thus no chemical change in the borehole fluid could besustained during drilling/coring operations while circulationis maintained. Continuous treatment of the seawater drillingfluid is not considered to be either necessary or practical.Under certain circumstances (stuck pipe, unusuallogging/sampling operations, etc.) where there is an influx ofH2S-bearing fluid and the drill string must remain in the holewithout circulation, there will be a provision for filling thehole with fluid containing chemical scavengers. Dependingupon the situation, the fluid will be fresh-water-basedbentonite mud, seawater-based sepiolite mud, or seawater. Thefluid will be mixed with a concentration of 5 lb/bbl ofironite sponge and 5 lb/bbl hydrated lime for scavenging H2Sand C02, respectively.
51
APPENDIX V
EMERGENCY TELEPHONE CONTACT NUMBERS
The following personnel should be notified in the eventof an H2S Emergency Condition II or III, or in theevent of uncontrollable backflow or steamflash:
R. M. Grout ODP
or
M. A. Storms ODP
C. V. Greif UDI
or
R. P. Nabholz UDI
The following regulatory agencies must be notified assoon as possible in the event of a H2S EmergencyCondition, or in the event of uncontrollable backflowor steamflash:
I. Emergency Condition II or III (Greater than 10ppm)
Office:Home:
Office:Home:
Office:Home:
Office:Home:
(409)(409)
(409)(409)
(409)(409)
(409)(409)
845-2144693-6410
845-2101696-8035
696-7955776-5840
696-7955774-4558
National Energy BoardF. Lepine
or
G. Yungblut
or
P. Ragusa
Office: (613) 991-2017Home: (613) 224-8302Fax: (613) 993-9897
Office: (613) 993-3760Home: (613) 722-9286
Office: (613) 991-2021Home: (613) 830-9350
52
II. Emergency Condition III (Greater than 50 ppm)
Canadian Coast Guard Via Radio: 2182 KHzVictoria, B.C. - Search & Rescue VH F16
Telephone: (604) 363-2333(800) 742-1313
The following hospital is the primary treatment centerfor any injuries:
Victoria General HospitalVictoria, B.C.Telephone: (604) 727-418124 hrs/day
The following helicopter service will be used forMedevac/emergency transport:
Pacific Rim HelicopterVancouver International AirportATTN: G. KearneyTelephone: (604) 276-001524 hrs/day
53
APPENDIX VI
AIR BREATHING CYLINDER RECHARGE STATION
AND 4 CYLINDER AIR BANK
AIR BREATHING EQUIP, (SCDTT AIR PACKS)
CASCADE - 8 BOTTLES, θ MASKS
CASCADE - 8 BDTTLES, 8 MASKS
CASCADE - 2 BOTTLES, 8 MASKS (PORTABLE UNIT)
CASCADE MANIFOLD
VINDSOCKS POSITIONED INDERRICK AT LOCATIONS CLEARLYVISIBLE FROM DECKS IN THEVICINITY OF THE DERRICK
DP CONTROL ROOMVINDSOCKDN STERN
AUX WAREHOUSE
REEFER LOCATED ONTOP OF CT SHOP
LIFE BOAT AREASPRIMARY SAFEBRIEFING AREA
6 EACH FOR RIG CREV
CORE RECEIVING DECK(BRIDGE DECK)
DP CONTRDL ROOMCORE LAB AREA(BRIDGE DECK)
CORE SPLITTING ROOM
CORE LAB ROOFOCEAN DRILLING PROGRAM
TEXAS Atüi UNPfWKSlTYα u w trim*, TX. TTM*
LAYOUT «. LOCATIONOf AIR BREATHING EQUIP. I WIND INDICATORS
© – CENTRAL CONTROL PANEL
[D]- DETECTOR UNIT & ALARM
(g)- PORTABLE MONITOR
- FIXED SENSOR
16 EACH FIXED SENSORS8 EACH FIXED DETECTORS8 EACH PORTABLE DETECTDRS1 EACH CENTRAL PANEL
LABS FRESH AIR INTAKE
ACCOMMODATION FRESH AIR INTAKE
[PORTABLE DETECTDRI CARRIED BY DERRICKMAN IAT ALL TIMES TO
• PUMP/MUD PIT AREASI * f- —I
© GD \®M BOTTOM STAIRVAY STORES ENTRANCE
ENTRANCE TOREEFER AREA
LOVER TWEEN DECKLOCATCB ONTOP OF CT SHOP-v
LOCATED ON IRDNROUGHNECK OR ABOVE
DRAVVORKS
CORE SPLITTING ROOM
INBOARD CENTER OF STBDDDG HOUSE ROOF
OCEAN DRILLING PROGRAMTKXAS Atüá VSlVtFSm
LAYOUT I LOCATION OF H,SDETECTORS AND SENSORS
BRIDGE TOP LEVEL ATT OF DP CONTROL ROOM\
11-CFM AIR COMPRESSOR<ELECTRIC)
LOCATION BRIDGE ROOF
173' HIGH PRESSURE FILL LINE<3 - 5C SECTIONS)
ΘΘΘΘ[©©Se.
C, 8 CYL. CASCADESTATION (RIG FLOOR)
(6-PORT MAWFOLDJ
TTTJTT
I
\(gXBXSXB)
I~l
j .
.OPTIONAL \I AIR MANIFOLD
IN DERRICK
LPH
s MINUTE: BREATHING AIR UNITS
LOW PRESSURE HDSE
100' HIGHPRESSURE
FILL LINE
4 CYL. AIR BANK(BUFFER)
AIR BANK TO BC PLUMBED IN SUCH AMANNER TO ALLOW EACH CASCADESTATION (Cp Cg, It Cy> TO BEINDEPENDENTLY FILLED WITH AIR.
13C HIGH PRESSURE FILL LINE(3 - 3C SECTIONS)
ΛCORE LAB
o o
C. <PORTABU:UNIT/SPANC>
MANIFOLD ATTACHEDTO CYL. CASCA9C
fe[6-PORT MANIFOLD]
ma\
I T U T U I
Ü Ö
j CT REEFER /SPARE
| (•-PORT MAMIT0L9
I H i i i J
&
\ y
\ y TΠLCKANCCS iM.cn NOTIDΠUCT•M * i/ 4
IiJ•II t t/
CDNCεNTRtCITV ALLDIAHfTCRS TIR .003
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LF.G 139 CASCADE STATION SCHEMATIC
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Breathing-air equipment
Conditions may develop which require air breathingmasks/respirators to be worn by personnel working in thedesignated hazardous areas. A proper seal between the surfaceof a respirator face piece and the wearer s skin isimperative. Facial hair, such as beards, sideburns,moustaches, and even a few days growth of stubble will preventa good seal. This results in the respirator permittingnegative air pressure inside the face piece during inhalation,and causing excessive penetration by an air contaminant.
Personnel wearing eyeglasses and contact lenses must takespecial precautions when wearing breathing equipment. The earpieces on the eyeglasses will interfere with the seal on theface mask of both the self contained breathing apparatus andthe cascade breathing system. Lens holders will be providedto mount eyeglasses inside the face masks with the ear piecesremoved.
Injuries have been sustained by personnel wearing contactlenses using breathing-air equipment. The positive pressurein the face mask can push the lens up inside the cavity of theeye. The positive air pressure also dries the eye out behindthe eye. Therefore, contact lenses should not be worn withthe breathing equipment face masks. Instead, a pair ofconventional glasses should be worn inside the face mask usingthe lens holder as described above.
PERSONNEL WORKING IN HAZARDOUS AREA(S)
Persons assigned tasks in the hazardous area(s) thatrequire the use of breathing equipment during situations shallnot have stubble, beards, sideburns, or moustaches.
SCIENTISTS WORKING IN THE LAB STACK
Those scientists that (1) have work activities confinedto the inside of the lab and (2) are not assigned emergencyduties may elect not to shave facial hair. If the individualelects not to shave facial hair, he must sign the statementprovided below.
My signature below (with witness) indicates that I havebeen informed of the dangers associated with using abreathing apparatus that might not suitably seal becauseof interfering facial hair and I choose not to hold theOcean Drilling Program responsible for any accidents,illness, or medical problems that might occur if itbecomes necessary for me to use a breathing apparatusduring an H2S emergency.
S igna tur e Date.
Witness Date.
(H2S Technician)