CO2 Transport and Storage Availability

Overview

High availability of CO2 Transportation and Storage networks will be essential for maximising the benefits of Carbon Capture Utilisation and Storage (CCUS) systems, and are an important aspect of commercial contracts between emitters and T&S operators. Planned or unexpected downtime in the T&S system has implications for the emitters, both commercially and potentially environmentally if they need to vent CO2 to the atmosphere. There may also be venting/outage challenges when crossing state or national borders.

The objective of this study is to investigate realistic rates of CO2 Transport and Storage operational availability that may be achievable for future systems, with a focus primarily on pipeline transportation and storage within sedimentary basins (saline aquifers and depleted fields). This study was undertaken by TNO with SINTEF and SCCS.

Summary

• Standardising liability frameworks, ownership transfer rules, and CO₂ purity
  standards could create a more cohesive international CCUS market and reduce
  risks associated with cross-border transport.
• At the T&S network level, the requirements of the injection wells place the most
  constraints on the system for safe operations.
• A connection from a single supplier to a single storage location will, in theory, be
  more vulnerable to intermittent or fluctuating CO2 supply, and capture is limited to
  the availability of storage.
• Designing for a system with terminals and multiple sources and storage sites with
  a possibility for overcapacity makes the system more robust and flexible.
• The costs for over-sizing infrastructure are potentially high.
• A complex system will likely require more extensive monitoring and supervision to
  maintain and optimise its operation.
• Operational time and maintenance schedules for existing networks are not readily
  available in open sources, but would be a valuable dataset for planning operations.
• Existing CO2 Transport & Storage networks have a range of different configurations and operating
  conditions, and future networks are likely to become increasingly complex with a
  wider range of operating conditions. These will partly depend on the phase of CO2
  transported, the location of the network (onshore or offshore), the type of
  pipeline (insulated vs non-insulated), the type of reservoir, and the complexity of
  the network.
• Downtime can potentially be minimised in the T&S network by designing for a
  degree of redundancy. Therefore, operations may not need to slow down or shut
  down, provided sufficient redundancy is built into the network. This can be
  achieved by building spare capacity into components of the CCUS chain. There is
  often a trade-off between the chance of an element failing and the costs of
  installing redundant capacity.
• Both tubing design and downhole chokes play a crucial role in managing CO2
  injection flexibility while ensuring safe and efficient well operations in depleted
  gas reservoirs.