Feasibility of Geological Carbon Dioxide Storage; From Exploration to Implementation

Abstract

This study utilises a range of techniques to investigate the feasibility of the geological storage of carbon dioxide. Three specific themes were addressed.

Saline aquifers have been proposed as an attractive geological storage medium due to the theoretical storage capacity offered, despite the poor quality and quantity of date available to appraise them. Published methodologies are numerous, which attempt to refine the uncertainty by the introduction of capacity coefficients producing estimates with a variance of up to five orders of magnitude. The source of this uncertainty is investigated using Monte Carlo based sensitivity on a North Sea case study site. This shows the limitations and sources of error inherent in the application of such method. A new method is proposed to account for the limited available input data.

Injectivity of geological reservoirs has been highlighted as a potential setback for CO₂ storage. Reservoir hosted compartmentalising membrane seals are shown to permit CO₂ migration without compromising storage integrity in three North Sea examples. The presence of oil as a wetting fluid in the substrate significantly reduces the capillary entry pressure of a membrane seal as a product of CO₂ water contact angle of cos 85° to cos 90°. Cross fault flow rates are shown to be on operational timescales.

CO₂ storage projects have been cancelled as a consequence of public objection. Public Engagement has been proven to affect the public’s perception of CCS in both positive and negative directions by facilitating informed decision making. The perception of trust and impartiality are demonstrated to outdo the perception of knowledge and experience. Furthermore the perceived benefits of CCS are evidenced to be tempered by person’s preordained perception either of the technology, or those who advocate it.