Background to the Study

Constructability is defined as the “optimum use of construction knowledge and experience in planning, design, procurement, and field operations to achieve overall project objectives”₁. Specific studies demonstrate that front-end constructability efforts result in a substantial return. Owners could save between 4.3 and 7.5 % in the total project cost and schedule respectively, meaning a 10 to 1 return on the constructability effort investment. 

1 Definition from the Construction Industry Institute (RECAP, 2017)

Although constructability and operational challenges have been identified in previous IEAGHG reports, some aspects were unique for those locations and status of the initial facilities.

IEAGHG identified the need to provide a guide on constructability and operation for new users, aiming to make the information available for the next generation of commercial plants, speed up their progress, and increase their success ratio. This study aims to provide information from large  CCUS projects to support the decisions during the transition from the planning to the execution phase.

Key messages

•    Key factors for the success of CCS projects include:  integration of the CCS system and the original facility early in the project development process, previous testing of the capture system under the specific conditions of the original facility, and involvement of the stakeholders from the early stages of the project. 
•    The business case and coordination of the cross-chain (including capture, transport, and use/storage), are essential to maintain the operation of the CCS project within the designated time-line. 
•    Other aspects for success include a detailed planning simulation of the construction site management, plant commissioning, start-up, maintenance, shutdown and decommissioning. 
•    This investigation has identified several reasons for cancellation of CCS projects.  These include: lack of long-term economic viability (including dependency on government subsidies and unexpected changes to government funding schemes); uncertainty around risk management and allocation; inadequate integration of the capture system with the original facility, or lack of planning in advance (including technical aspects not related to the CCUS system); and flawed design. 
•    The decision tool proposed in this study is based on the ability to make and then integrate individual decisions.  The tool can generate favourable and less favourable options for each decision.  However, these selections need to be tailored to the site-specific conditions.
•    Although the decision tool is presented as a linear process, some decisions could be taken in parallel or as an iterative process to find the optimum tailored design.  The tool has the ability to refine initial decisions or retain selected decisions for later stages.