Production on several fields is approaching the end of profitable operations. This means that an increasing number of facilities and more equipment will be partially or completely removed in the years to come; or possibly disposed of in other ways. These work operations entail multiple critical activities from a safety point of view.
The Petroleum Safety Authority (PSA) is responsible for supervision of the activities until the facility to be removed (or parts thereof) has/have been brought on board a vessel.
The Petroleum Act requires the developer of a field to pay for and to carry out – including full or partial removal of facilities and equipment after the production period has ended. The removal work must take place pursuant to the HSE regulations for the petroleum activities, and on the basis of considerations including consent and decommissioning plans.
The decommissioning plan describes HSE factors related to the actual removal operation on the field and the measures that are implemented to ensure a prudent health, safety and environment standard, including risk, analyses, methods, operations, consequences, factors to ensure prudent implementation and measures to prevent pollution.
The application for consent also describes the roles and responsibilities of the various players involved in the operations.
Heavy lifts and chemical substances
Crane and lifting operations are among the main HSE challenges, and they are a significant contributor to the risk scenario in the petroleum activities. The removal phase is characterised by particularly heavy and complex lifting operations.
Inadequate management and guidance, defective equipment and maintenance, as well as deficiencies in procedures and the use thereof, are among the most frequent causes of undesirable incidents.
Therefore, it is important that lifting operations in the removal phase are planned and carried out on the basis of an overall assessment, approach and organisation.
Hot work (burning, sectioning, cutting, grinding, welding, etc.) has a limited scope offshore, and is subject to strict safety and working environment requirements for preparation and implementation. In connection with scrapping, materials and components may contain chemical substances that are hazardous to health. Hot work entails a risk of exposure to dust, noise and toxic fumes.
Work in the removal phase will often entail a number of activities that take place at the same time, and which could conflict with each other without comprehensive risk management, such as removal of paint, torch cutting and purging of hydrocarbons confined in tanks and pipes.
Important lessons learned
Two major removal operations have been initiated so far on the Norwegian shelf – on the Frigg field operated by Total and on the Ekofisk field operated by ConocoPhillips. The experience gained in these projects will be extremely valuable for subsequent removal activities.
Since an increasing number of facilities and more equipment will be removed and scrapped in the years to come, we must further develop our knowledge about chemical health hazards and other types of risk this work entails. Similarly, it is important that ease and simplicity of removal is considered when new facilities are designed and engineered.
Different authorities, different regulations
During the removal phase, the PSA is responsible until the facility (or parts thereof) has/have been brought on board a vessel. From that point in time, the responsibility is transferred to the authorities in the country where the vessel is registered, which means the Norwegian Maritime Directorate if the vessel is Norwegian. The Norwegian Labour Inspection Authority has regulatory responsibility for the scrapping site on land.
As regards factors related to the external environment, the SFT is the authority throughout all phases. The SFT is subject to the PSA's coordination when the activities are defined as petroleum activities under the Petroleum Act.
Relevant HMS regulations for the petroleum activities:
- Framework Regulations, Section 22 relating to decommissioning plan with description of risk, analyses, methods, operations, consequences, measures to ensure prudent implementation, measures to prevent pollution
- Information Duty Regulations, Section 5 relating to consent for certain petroleum activities, litra g) prior to disposal of a facility, even if a decision relating to disposal has been made pursuant to Section 5-3 of the Petroleum Act