The elements of safety related to cost effective design of subsea system design, should be given due consideration at an early stage in project development. Traditional risk analysis may be utilized using the combined effect of probability and consequence cost to determine the individual "Cost of Risk"and the cost of reducing the rlsk, allowing the designer to include the safety aspects also when he is optimizing his design. The paper presents a model which demonstrates a methodology for evaluating the cost effectiveness of alternative safety measures for protection of a subsea installation. The model considers the "Cost of Risk" and the reduction in risk when a safety measure is introduced. This is compared to the initial investment costs related to the introduction of the safety measure and the possible·increases in operational costs. The paper presents the methodology as well as results from applications of the model to a multi-well template.
In order to assure cost-effective design of subsea production systems, safety activities should also be integrated in the early project development phases. Many important aspects and potential problems with respect to safe and reliable operations of subsea production systems, may be identified and sorted out in the early stages of system design. Generally the cost impact of design changes will increase with time, implying that the flexibility for making changes decrease. Hence, the cost impact of safety related design requirements may be very high if they are introduced late in the project development. This may lead to safety improvements being regarded as added costs only. Our assertion is on the contrary that safety activities are profitable business throughout all phases of a project life. First of all, early identification of potential problems will make it possible to solve the problems at a lower cost.