Overview

During the assessment phase, it maybe necessary to assess a number of different technical options and to select the solution which best meets the SRD and therefore the URD. From a safety prospective, it is necessary to consider the compliance with the Safety Requirements of each option and the safety hazards presented by each option, as it is conceivable that the best technical option is intolerably unsafe and should not be progressed.

Task

Task A – Hazard Identification

You will need to review the three technical options and undertake hazard analysis of each option:

  • Use the general checklist from ASEMS SMP04 to help identify hazards [Hint: you may want to refer back to the preliminary hazard identification output]

When identifying hazards, you may wish to consider:

  • Safety related interfaces between the various elements of the system
  • New hazards introduced by the different options
  • Human error
  • Maintenance and emergency procedures
  • Defence against common mode failures

Team C - Option 1 - Hazard Log

wdt_ID Hazard ID Hazard Title / Description Causes Control / Safeguards Accident Sequence Accident Description Accident Severity Accident Frequency Risk Class Recommendations / Actions ALARP Argument
195 1 Uncontained Flammable/Combustible substances leaking into occupied spaces leading to harm to equipment, systems, or people Leak or Spillage Gauges and Alarms, Leak Kit A material defect or containment failure in the pipework from hydrocarbon separator to the flame causes a small leakage that can propagate to rest of the platform causing to a slow build up of high concentration of combustible gas in a confined area. Death, burns, loss of limb, blindness, deafness, impact/crushing,cuts/bruises/abrasion, asphyxiation and exposure carcinogenic compounds Catastrophic - Multiple deaths Improbable - Unlikely but may occur (e.g. every five years C Enact the Control/Safeguards, do RCM, implement controlled access areas. Design to approved standards. Provide ATEX equipment to reduce spark incidences, prohibition of smoking and other naked flames. Atmospheric monitoring.
196 2 Exposure to Uncontained Explosive Gas

 Leak from pipework, Equipment Failure, value failure, Pipe corrosion/errosion, Impact to pipework, Hostile Action Gauges and Alarms, air quality monitors, sensors. Ventilation systems, working procedures, maintenance schedule, fault detection, auto stops, barriers, protected pipework

Post control methodology - First aid, Evacuation procedures, Barriers and alarms, 		Leak of Explosive gas caused by equipment failure, resulting in uncontained explosive gas, resulting in personnel being exposed to uncontained gas which may cause asphyxiation, chemical injury. Death, asphyxiation, burns, chemical injury, blindness, deafness Critical - A single death; and/or multiple severe injuries or severe occupational illnesses Improbable - Unlikely but may occur (e.g. every five years C Enact the Control/Safeguards, do RCM, implement controlled access areas
197 3 Pressures within pressurised systems out with nominal in occupied spaces and spaces with critical equipment Blockages, PRV failure Gauges and Alarms Blockage due in line causes build up of pressure and equipment is operating outside on nominal pressure range. Lead to mechanical breakup of assembly and ballistic fragments are released Death, loss of limb, deafness, impact/crushing, cuts/bruises/abrasion Critical - A single death; and/or multiple severe injuries or severe occupational illnesses Improbable - Unlikely but may occur (e.g. every five years C Enact the Control/Safeguards, do RCM, implement controlled access areas, installation of PRVs, testing, caging solution
198 4 Uncontrolled HP Air release from Pneumatic Pump resulting in harm to equipment, systems, or people Fault in the HP Air Pneumatic Pump arrangement Enclosed the Pneumatic Pump in a casing, within a controlled access area HP Air Pneumatic Pump pipework or connection becomes loose, resulting in HP Air leakage, which could lead to a nearby item moving (causing impact to worker), or direct impact to a worker Impact, cuts/bruises/abrasion Marginal - A single sever injury or occupational illness; and/or multiple minor injuries or minor occupational illnesses Occasional - Likely to occur several times (e.g. annually) C Enact the Control/Safeguards, do RCM, implement controlled access areas N/A
199 5 Unexpected fault in the Control System functionality resulting in harm to equipment, systems, or people A bug/virus has entered the control system, due to a worker plugging in an unauthorised peripheral into the Control System Allow only authorised peripherals to be plugged into the Control System. Ensure passwords are used for Control System access Worker plugs in unauthorised peripheral, Control System functionality changes or elements of it become inoperable, thus, the Control System loses configuration & control of the Oil SSTS Death, loss of limb, blindness, deafness, impact/crushing, cuts/bruises/abrasion Critical - A single death; and/or multiple severe injuries or severe occupational illnesses Incredible - Extremely unlikely that the event will occur at all given the assumptions recorded about the domain and the system D Enact the Control/Safeguards N/A
201 6 Exposure to Noise above 90dbA Equipment Failure, Pump Fault System Complies with Control of Noise Regulations with peak levels no greater than 90dbA, Maintenance Scheldules, PPE, A Fault occurs causing Noise to exceed 90dbA, causing personnel to be exposed to Noise levels that exceed safe limits causing Hearing damage. Hearing-Related Injuries, Vestibular Damage Marginal - A single sever injury or occupational illness; and/or multiple minor injuries or minor occupational illnesses Remote - Likely to occur sometimes (e.g. every two years) D Ensure correct procedures in event of equipment failure, Enact the Control/Safeguards, do RCM, implement controlled access areas

Team C - Option 2 - Hazard Log

wdt_ID Hazard ID Hazard Title / Description Causes Control / Safeguards Accident Sequence Accident Description Accident Severity Accident Frequency Risk Class Recommendations / Actions ALARP Argument
100 Death N/A

Team C - Option 3 - Hazard Log

wdt_ID Hazard ID Hazard Title / Description Causes Control / Safeguards Accident Sequence Accident Description Accident Severity Accident Frequency Risk Class Recommendations / Actions ALARP Argument
135 The fluid to the Water Conditioning may overfill, resulting in a flooding event. Use of a manual valve, may not have been opened effectively, resulting in a backflow of fluid to the wider Oil Rig Clearly label the valve of its "open" and "closed" positions so operator understands the valve setting Operator ineffectively opens the valve fully open -> backfeed of fluid builds up -> fluid floods out of the Water Conditioning arrangement -> Oil Rig gets flooded. Flood damage to Oil Rig Marginal - A single sever injury or occupational illness; and/or multiple minor injuries or minor occupational illnesses Improbable - Unlikely but may occur (e.g. every five years D Ensure SOP in place for valve operation of Water Conditioning N/A
140 Mild excess pressure in the flow from the well head to the separator causing seperator failure causing leak of contaminated water, explosive cases, and oil. A pipework obstruction causes a mild rise in pressure. The butterfly valve (rated 25bar) fails and causes 25bar exposure to the seperator causing it to fail. Increase in pressure monitored by pressure sensor upstream of butterfly valve. Robust valve design and quick acting valve. Pressure rises in well head supply causing butterfly valve to fail leading to increase pressure flow to seperator. Seperator fails and containment of the extracted hydrocarbons is compromised leading to explosive, corrosive and carcinogenic compounds released. Loss of life, permanent disfigurement, long term health implications, burns Catastrophic - Multiple deaths Incredible - Extremely unlikely that the event will occur at all given the assumptions recorded about the domain and the system C Replacement of higher FoS valves on well head to seperator line.
Inclusion of PRVs upstream

141 Build up of combustible gas in flame tower pipework Workers do not open or close valve when required Change valve to automatic and link to pressure sensor. Pressure builds inflame tower pipework, pressure sensor alarms go off but valve not opened in time, causing explosion. Death, burns, loss of limb, blindness, deafness, impact/crushing,cuts/bruises/abrasion, asphyxiation and exposure carcinogenic compounds Catastrophic - Multiple deaths Incredible - Extremely unlikely that the event will occur at all given the assumptions recorded about the domain and the system C Include a PRV in design, include SOPs in place for valve operation. To classify this risk as ALARP, the following activities need to take place:

1. Firstly, to identify whether the risk/hazard can be avoided. In this case, no as the gas is a by-product of the process.
2. In this case, the gas nor pipework cannot be substituted.
3. Ensure design is compliant with good practice, legislation and regulations
4. Cost Benefit Analysis (CBA), including relevant disproportion factors depending on severity of hazard. of the following:
- Change of valve type to a PRV in the pipe.
- Change from manual valve operation to automated valve operation.
5. Training and Operating procedures should also be implemented.
6. Implementation of appropriate risk control measures.
7.All actions in hazard log have been carried out.


142 2 Exposure to Electrical Sources from the Electrical Pump Fault/ Failure of the Electrical Pump Earths, Electrical Safety standards, Fault occurs within the Electrical Pump causing electricity to arc causing electrical related injuries Electrical Related injuries, electrocution, shock Marginal - A single sever injury or occupational illness; and/or multiple minor injuries or minor occupational illnesses Improbable - Unlikely but may occur (e.g. every five years D Ensure design mitigates electrical related faults
143 Over-pressure of SSTS System downstream of the Pump Greater flow through pipework 25bar, Pump operates at greater than 25 bar Engineering Controls : Pressure Guage and alarm
Soft: Change in processes, allow for greater time for activities
The Pump operates at a flow greater than 25 bar causing overpressure within the system, pipework ruptures causing spillage and potential projectile. Environmental Spillage, Projectile, Slips Trips and Falls, Impact injury, Death, Crush injury, drowning, chemical injury. Critical - A single death; and/or multiple severe injuries or severe occupational illnesses Remote - Likely to occur sometimes (e.g. every two years) C

Task B – Risk Assessment

For each option above, complete a risk assessment of all identified hazards, using the definitions and the matrix provided below.

Severity Definitions

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Frequency Definitions

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Risk Matrix

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Risk Class Definitions

Conclusion

Now that you have completed the hazard analysis of the three technical options, update the Padlet below to capture:

  • Your findings from the hazard analysis of each option
  • Which is your preferred option, based upon the outcome from the hazard analysis, and justify your selection

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