An evaluation of hydrocarbon deposit tightness in aspect of CO₂ sequestration

Abstract

Depleted hydrocarbon deposits due to large capacity and proven tightness are often considered as prime candidates for $CO_2$ sequestration in geological structures. The tightness of these structures is mainly connected with the exis-tence of water saturated overbunden rocks of very low permeability which form a natural barrier for the migration of hydrocarbons. This paper explains the sealing mechanisms of caprocks resulting from capillary forces at the interface of hydrocarbon – water and carbon dioxide – water contact. Other ways of caprock leakage due to rock fracturing or reactivation of natural faults and fi ssures were also investigated.