Specialized Safety Advisory

DEKRA India has competencies in many safety studies specific to the oil & gas industry

Bow-Tie analysis is a hazard analysis technique which is combination of fault tree analysis (FTA) and event tree analysis (ETA). Fault tree analysis (FTA) is identifying basic events that can lead to an accident event, whereas Event tree analysis (ETA) is identifying the event sequences from initiating events to accident scenarios. The Bow-Tie approach is highly effective for initial PHAs to ensure high probability-high consequence events have been identified and addressed.

Dynamic RAM is an efficient method for reducing design, operations and contractual cost of projects by means of the following:

  • It ensures that return on investment is as per expectations by ascertaining the design requirements to meet contractual productivity target
  • It assesses the changes in CAPEX required for different levels of redundancy and sparing, and trade this off against the OPEX costs develop maintenance and sparing strategies
  • It confirms the redundancy of different system elements
  • It predicts productivity shortfall
  • It can help assess and develop make-up strategies upon expected shortfall in productivity
  • It can determine operational constraints
  • It can define spares locations, supply logistics and storage cost
  • It can develop commonality of spares and help reduce investment in spares holding
  • It can define resource allocation and hence help assess resource requirement to meet target productivity
  • It can define maintenance schedules in line with the target or contractual productivity
  • It can include cost of maintenance and repairs in the model to help assess cost profile over the life of a facility

Quantitative Risk Assessment has been long established in the Oil & Gas industry and combines hazard identification with an assessment of the frequency and magnitude of hazardous events to determine the risk(s), which is evaluated against tolerability criteria. Full QRA studies frequently encompass several risk management aspects, e.g. modelling of system behaviour, system reliability and the effectiveness of safety systems. Conventional QRA has been extended by DEKRA in applications such as Deconstruction Risk Assessment and Typhoon Risk Assessment depending on the local conditions and client requirements.

Safety Critical Elements will be defined and identified in accordance with DEKRA criteria. Having identified critical elements each is assigned performance standards that defines essential measures provided to manage major accident hazards and events requiring escape, mustering, evacuation, and rescue.

A key component in safety management is preparedness and anticipation for any untoward situation or circumstance. The ERP then serves as a vehicle to address the level of preparedness and anticipation in light of possible emergency scenarios. Through an extensive examination of the processes, materials and systems at a facility, DEKRA Group can explore the various emergency scenarios and establish the required actions. The ERP will therefore articulate specific responsibilities and action needed under various emergencies. A comprehensive and detailed ERP demonstrates the capability of a facility to adequately anticipate and respond to emergencies thereby enhancing the reputation and integrity of the organization.

The objective of the smoke and toxic gas analysis is to analyse the hazardous events which have been identified in the HAZID and which will lead to the impairment of escape and evacuation routes or Temporary Refuge (TR) (if applicable).
Escape routes can be impaired by either smoke or toxic gas engulfment, or catastrophic events to the installation that could lead to the loss of the facility. The effects of these hazards are assessed to determine what will impair the escape routes and TR. The integrity of the escape routes will be evaluated based on relevant impairment criteria.

TR is provided on offshore installations to enable orderly muster, evacuation of personnel during an emergency. DEKRA Group has performed TR Analysis to assess its integrity under major accidental events on an offshore installation.

EERA is part of Formal Safety Assessment (FSA). DEKRA Group has performed EERA to assess the risk associated with Evacuation, Escape and Rescue activities following an accidental event on an offshore installation.

ESSA is part of FSA. DEKRA Group has performed ESSA to assess the risk associated with failure of emergency systems due to an accidental event on an offshore installation.

Using F&G Mapping techniques, the number and layout of flame, flammable gas and toxic gas detectors can be optimised by performing geometric calculations on the 3D model. The analysis is fully three-dimensional and gives confidence that defined performance targets are being met. The resulting detector locations typically give significantly improved detection coverage over more traditional rule-of-thumb approaches to installing detectors. Full three-dimensional CFD simulations are also used to provide more accurate and firm study bases to avoid over-conservatism in the number of detectors used.

Consequence assessment is a rigorous and methodical examination of the direct undesirable impacts of a loss of containment of material or energy, including fires and explosions and potential toxic impact from the release of these chemicals. It is carried out via mathematical Source Models/Discharge Models software like DNV GL PHAST. A list of MCA’s (Maximum Credible Accident) is prepared on the basis of the loss of containment of material/energy incidents and to limit the total number of outcome cases in a manageable manner. Then quantitative results in terms of flammable consequence impact zones and toxic dispersion impact zones are obtained with the help of PHAST software.

Process vent design requires careful consideration of hazard and risk factors such as thermal radiation, flammables/Toxic dispersion. These parameters are required to be assessed in order to define adequate stack height, separation from adjacent facilities and to define any sterile zone.
It is also conducted in order to identify the flammable/toxic gas dispersion impact on sensitive receptors which is defined as an area or location which is vulnerable to the effects of gas dispersion such as temperature impact, gas toxicity, oxygen deficiency or flammability.

Explosion Modelling can be done with the help of Computational Fluid Dynamics (CFD) Simulations. Explosion simulations are performed with varying gas cloud locations, gas cloud sizes and ignition locations, in order to establish the potential explosion overpressures at blast walls and critical locations, piping and critical equipment elements. The explosion risk based on the time dependent ignition model and establish frequency of exceeding overpressure curves for the blast wall and relevant deck elements, piping, equipment elements etc is then calculated. The objective of the study is to calculate explosion loads and explosion risk in the areas.

In order to alleviate emergency conditions, hydrocarbon processing facilities commonly include the provision of a flare into the design. However, the excessive radiation levels from the flare could lead to personnel and assets being susceptible to impact. In order to assess this, flare radiation studies are performed to predict the thermal intensities arising from the flare. These results provide an important basis in ensuring that the design of the flare is fit for purpose and does not expose any personnel or assets to excessive thermal radiation.

The ATEX Directive requires the employer to demonstrate, that he has taken all technical and/or organisational measures to reduce the risk from dangerous substances, so far as is reasonably practicable. Where the nature of the activity precludes elimination of the risk, the employer should remove initiation events, such as sources of ignition, and install equipment to mitigate the detrimental effects of an explosion or other energetic event. Where necessary these measures should be combined and/or supplemented with measures to prevent the propagation of explosions. DEKRA Group has developed a comprehensive phase-wise approach that works in partners with the employer to achieve compliance in a focussed and efficient way.
These phases include:

  • Initial Assessment
  • Detailed Studies (such as Fire and Explosion Assessment, Electrostatic hazard assessment, etc.)
  • Overall Risk Assessment
  • Verification & Documentation

FERA provides a safe basis for designing Hazardous processing and storage facilities. This is accomplished through a structured and quantified approach towards assessing and minimizing the effects of fire and explosion hazards on the adjacent facilities or any sensitive receptors e.g. control room, administrative building . It can be carried out at concept and design stages to identify major accident (dimensioning) events and verify the suitability of applied fire safety provisions.

The movement of fluids through an enclosed space or opening often leads to the generation of noise (i.e. noise energy) within the closed system which is further translated into vibration, hence the term acoustically induced vibration or AIV. Since standard design codes and standards do not provide an effective means of assessing the capability for such vibration, AIV is often neglected thereby subjecting the system to possible structural failure. DEKRA Group’s AIV programme calculates the acoustic energy within a system which can then be assessed against industry criteria as necessary and suitable recommendations proposed as required. This eliminates the need for costly and time-consuming repairs which may be necessitated by failure of the system due to unmitigated AIV.

Prolonged exposure to excessive noise levels has been shown to cause various ill-effects ranging from the inability to be productive at work due to a loss of concentration to complete loss of hearing. In order to avoid such impacts from being realised, noise abatement studies are undertaken to identify the required mitigation to protect personnel from such exposures. DEKRA Group’s noise prediction model is able to simulate the propagation of noise and illustrate these results in the form of noise contours. Drawing of these results, suitable recommendations such as hearing protection, noise enclosures, etc. can then be proposed and incorporated into the design of the facility.

Dropped Object Analysis evaluates consequential risk to the plant, offshore platform structure, pipelines and personnel as offshore installation perform frequent lifts of varies objects of different impact energy. DEKRA Group has performed Dropped Objects Analysis to assess and mitigate this risk for offshore installations.

Ship collision risk to an offshore installation can be significant due to high marine traffic in the area. DEKRA Group has performed Collision Risk Analysis to assess and mitigate ship collision risks through appropriate navigation systems, marine procedures and review of an offshore installation’s structural integrity.