Risk Assessment and Management for CO2 Capture and Transport Facilities

Abstract

When discussing risk assessment and risk management related to Carbon Capture, transportation and Storage (CCS) the attention usually focuses on risk related to storage. However, planning and designing a CCS value chain will also require demonstrating the risk associated with carbon dioxide capture and transport is satisfactorily managed.Risk related to processing and transport of carbon dioxide is not a totally new aspect, but the amounts processed and contained as well as the physical state in which carbon dioxide will be handled is outside the boundaries of today's industrial application of carbon dioxide.As a project progresses from feasibility study via front end engineering to detail engineering, construction and finally commissioning and normal operation, the amount of input data for a risk assessment of course increases. It may thus be tempting to delay the safety risk assessment in the early stages as it can be done more accurately at a later stage. However, early identification of safety issues can usually enable those issues be resolved with much less impact to a project's budget and schedule and therefore this opportunity should not be lost. It should be noted that safety concerns are commonly cited in objections for CCS projects and therefore getting an early understanding of the safety risk will also help gain acceptance and support.This paper will present an evaluation of the typical level of risk assessment done in early phases of a CCS project, including a review of the risk analyses performed in the Front End Engineering and Design (FEED) for selected CCS projects. Moreover, experiences from the risk for carbon dioxide pipelines as well as processing and injection will be included.Challenges related to risk assessment at each stage in the project, from feasibility study to normal operation, will be discussed. Risk management measures, both of the preventive and of the consequence mitigating type, that should be included within a project risk assessment and evaluations, will also be included in the discussions.For the early stages the focus will be on how to identify hazards that may have a significant impact and/or be costly to mitigate at a later stage. The paper will focus on strengths and weaknesses of approaches and methods applied, and will provide guidance on their selection and use.As the project progresses, the attention will shift to managing the residual risk with the quantification and specification of design load requirements. For quantitative risk analysis the paper will give an overview of available risk analysis tools and their capabilities, with emphasis on modelling consequences of loss of containment.Loss of containment of carbon dioxide encompasses an extensive range of widely different scenarios. Most dispersion modelling tools will be capable of predicting the development of some scenarios, while other scenarios may represent a yet insurmountable challenge for one tool on its own. A range of predictable loss of containment scenarios will be presented, with an evaluation of the capabilities of selected tools for modelling these scenarios. Further, practical examples from quantitative risk analyses on supplementing integral dispersion models by computational flow dynamics models as well as simple calculations and available data will be given.