DESIGN CRITERIA FOR FIRE AND BLAST ENGINEERING IN THE GOAL SETTING WORKING ENVIRONMENT

摘要

The present goal-setting approach to safety on offshore installations in the UK Continental Shelf (UKCS) (1) means that new oil and gas installations must be designed to sufficiently resist potential accidental loads. Furthermore, the operator's management system must both enable safe operation of the installation and provide adequate response to accidents, should they occur, A goal-setting approach also allows other "goals" such as environmental issues or continuity of hydrocarbon production targets to be defined and then integrated and optimised within the whole design and operation of an oil or gas installation. One of the major advantages this approach offers is common defined criteria which both risk practitioners and engineers can understand and relate to. In the past, design criteria for fire and blast have been prescriptive and component based. In reality, however, an oil or gas installation fulfils its objectives as a whole system, i.e. all its parts and components act together, often in a time-dependent manner. A system approach has been possible in the past for normal operational loads, e.g. on structures and pipework. However, for accidental or upset conditions, only the relatively recent advances in computerised techniques enabled simulation of system behaviour under dynamic and ultimate limit state conditions with acceptable accuracy. Operational performance criteria can be established for an oil or gas installation on the basis of reservoir data, product characteristics and commercial constraints which may exist for the development of a hydrocarbon field. In addition, the operator's corporate risk criteria will set performance criteria for systems under accidental load conditions. The overall system, i.e. the installation, can then be designed to achieve the performance criteria for both operational and accidental conditions utilising the full interaction between subsystems and components of the installation. Predictions of interaction between sub-systems requires close cooperation between the various disciplines involved. Therefore, in order to fully utilise the benefits of system approach, changes to traditional working practices may be required. Advanced analytical methods applied at key phases in the design process and integrated multi-discipline team work at critical points of the design will be beneficial. As a result, significant cost savings both in design, materials, fabrication and operations can be achieved.