Safety is a top priority in the oil and gas industry. Marex employs a team of highly qualified Risk and Safety Engineers, Master Mariners, Marine Engineers and Naval Architects to oversee the delivery of a professional, consultative and cost effective solution to the offshore industry’s marine and safety needs.
In 2015 the EU directive on Safety of Offshore Oil and Gas Operations introduced changes to UK Safety Case regulation, resulting in the implementation of the Offshore Installations (Offshore Safety Directive) (Safety Case etc.) Regulations 2015 (SCR15). These regulations apply to all installations engaged in oil and gas operations in territorial sea adjacent to Great Britain and any designated area within the United Kingdom Continental Shelf. The regulations aim to reduce, as far as possible, the occurrence of major accidents relating to offshore oil and gas operations and to limit their consequences. One of the major changes from the previous regulations was the requirement to consider the potential environmental impact of a major accident.
Since the implementation of SCR15, Marex has completed over 10 safety cases for major drilling contractors in the industry and conducted thorough reviews of safety cases for some of the biggest names in oil and gas. This puts Marex’s highly skilled team members in an excellent position to assist companies with the revision of safety cases for SCR15.
One of the key requirements of SCR15 is that each offshore installation should establish a verification scheme to ensure that the installation’s Safety and Environmental Critical Elements (SECEs) remain in good repair and condition.
SECEs are defined as those parts of an installation or of its plant, the failure of which could cause or contribute substantially to a major accident, or the purpose of which is to prevent or limit the effect of a major accident.
The verification scheme is a statement of the suitability of the record of safety and environmentally critical elements and the scheme of maintenance.
The verification scheme establishes a system which ensures efficient operation of the installation through the continual review of the SECEs. Each SECE has an associated performance standard, which demonstrates their suitability, state of repair and condition based on function, reliability and availability.
For non-production installations, a verification scheme must be in place before commencement of any oil and gas operations in UK offshore waters.
The verification scheme is a live document, which must be reviewed and updated as often as appropriate and the provisions for such should be outlined within the document. As a minimum the following should be considered during the review of the verification scheme:
- Any development which could alter the SECEs
- Anything which affects the verification arrangements appropriate to them
- Matters which change the nature or frequency of verification activities
This review could potentially lead to a revision or replacement of the verification scheme.
Any changes to the operation of the installation that may change the requirements of the SECEs will result in a revision of the verification scheme and the associated performance standards, for example the conversion of an installation from non-production to production.
By ensuring the SECEs meet their required performance standards the duty holder provides some assurance that the SECEs are suitable and remain in good repair and so minimise the likelihood and potential consequences of a major accident.
A performance standard is developed for each SECE and included within the verification scheme. The performance standard states the required performance of the system described in terms of functionality, reliability, availability and survivability, against which the suitability and condition of the equipment can be assessed.
It is required by SCR15 that a description of the verification scheme is provided within the installation’s safety case, including the following details:
- Examination and testing of SECEs by independent and competent verifiers
- Verification of design, standard, certification or other system of conformity of SECEs
- Examination of work in progress
- Reporting of any instances of non-compliance
Identification of SECEs
The safety and environmentally critical elements for the installation must be identified before an effective verification scheme can be developed.
It is necessary to undertake a systematic approach to identify those systems which are SECEs. Within these systems many of the individual components may by SECEs, but others may not. SECEs include those systems for detection, control and mitigation of major accidents along with those systems which increase reliability through redundancy. This list of SECEs will vary depending on the installation’s design and operations. There may also be SECEs introduced for limited activities such as combined operations.
For example the BOP on an offshore drilling unit would be considered a SECE and a performance standard for it would be included in the verification scheme.
The starting point for the exercise to identify SECEs would be the identification and qualitative risk assessment of the major accident hazards associated with the installation operations. The risk assessment should identify the threats and potential consequences associated with each major accident hazard, as well are the measures which are in place to prevent occurrence of the major accident and to mitigate the potential consequences.
In order to help our clients demonstrate compliance with the safety case regulations and to show that the major accident hazards associated with the operation of the installation have been subject to appropriate risk assessment, Marex facilitates bowtie workshops which are designed to enable the identified major accident hazards to be qualitatively risk assessed by relevant stakeholders, including the rig crew. In order to do this BowtieXP software is used. When running workshops to align with the new requirements of SCR15 one of the main aims is to identify the equipment barriers associated with the control of major accident hazards, including those which could have a major environmental impact. It is therefore important to qualitatively assess the environmental risk associated with each major accident hazard, as well as ensuring that sufficient barriers are in place such that all risks associated with identified major accident hazards continue to be as low as reasonably practicable (ALARP).
Each scenario is represented by its own bowtie, such as the one below.
A bowtie diagram presents the hazards and their controls in a logical and structured manner. It can serve several purposes, e.g. as a methodology for identifying barrier functions and elements related to present hazards as well as communicating risks and control mechanisms efficiently.
Any structure, plant, equipment, system or component part whose failure could cause or contribute to a major accident is a safety and environmentally critical element, as is any which is intended to prevent or limit the effect of a major accident. The bowtie diagram is made up of the following components:
- Hazard – an intrinsic property of anything with the potential to cause harm
- Top-event – initial consequence that occurs immediately after the hazard is released
- Threat – potential to cause the top event
- Consequence – event or chain of events that results from the release of a hazard
- Barrier – measure that reduces the probability of releasing a hazard
- Escalation factor – condition that can cause a barrier to fail
The barriers can be classed as people, plant or process barriers. With regards to the verification scheme, the most important of these are the plant barriers as they will help us to identify SECEs. Details of the personnel responsible for the operation and/or maintenance of the barriers are also included. A typical plant barrier is shown below.
This barrier is for the BOP system and tagged on it are the two relevant SECEs (SECE 01 – BOP and SECE 02 – BOP Control System), as well as the person responsible (in this example the Subsea Engineer). Every barrier for each of the identified major accident hazard scenarios is tagged similarly to the barrier shown here with the appropriate associated SECE.
Oil and gas is a fast paced industry where low probability events with catastrophic consequences could easily be overlooked. It is important to ensure that every eventuality has been identified and assessed for all potential outcomes. The introduction of SECEs and the emphasis placed on the verification scheme and performance standards through SCR15 has helped to prevent and mitigate these major accident hazards.
Marex continues to provide a high standard of work for its clients, which in turn enables them to fully demonstrate compliance with SCR15 ensuring all aspects of workplace risk and safety have been accounted for through identifying, minimising and eliminating the risks to their employees, their assets and the environment.
For more information please visit: www.mmass.co.uk