Modelling acid attack of oilwell cement exposed to carbonated brine

• Published in: International Journal of Greenhouse Gas Control
• Main Authors: Liaudat, Joaquín, Martínez Estévez, Ariadna, López Garello, Carlos María, Carol, Ignacio
• Other Authors: Universitat Politècnica de Catalunya. Departament d'Enginyeria Civil i Ambiental, Universitat Politècnica de Catalunya. MECMAT - Mecànica de Materials
• Format: Article in Journal/Newspaper
• Language: English
• Published: John Gale 2018
• Subjects: Àrees temàtiques de la UPC::Desenvolupament humà i sostenible::Enginyeria ambiental::Tractament d'emissions i olors; Carbon sequestration; Carbonation Carbon sequestration Well cementCO2 carbonic acid Chemical model Finite Element Method; Anhídrid carbònic > Aspectes ambientals; Carbonic acid
• Online Access: http://hdl.handle.net/2117/114308; https://doi.org/10.1016/j.ijggc.2017.11.015

A diffusion-reaction model for the carbonation process of oilwell cement exposed to carbonated brine under CO2 geological storage conditions is presented. The formulation consists of two main diffusion/reaction field equations for the concentrations of aqueous calcium and carbon species in the pore solution of the hardened cement paste, complemented by two diffusion-only field equations for chloride and alkalis concentrations, and by a number of chemical kinetics and chemical equilibrium equations. The volume fraction distribution of the solid constituents of the hardened cement paste and the reaction products evolve with the progress of the reaction, determining the diffusivity properties of the material. The model is used to simulate experimental tests performed by Duguid and Scherer (2010), leading to promising results indicating that the fundamental aspects of the phenomenon are captured. Peer Reviewed Postprint (author's final draft)