First Implementation of Self-Healing Carbon-Dioxide-Resistant Cement System Using Perforate, Wash, and Cement Technique

Abstract An operator in Malaysia launched a carbon capture and storage (CCS) project targets to capture of 3.7 million metric tonnes (MMt) of carbon dioxide (CO2) annually, totalling approximately 80 MMt over 25 years. The success of CCS projects hinges on the integrity of the storage site, particularly the wellbore and surrounding formations. Cementing plays a critical role in ensuring long-term CO2 containment. This project involves reinjecting CO2 into a depleted reservoir, necessitating the conversion of legacy wells into CCS wells - a process that presents challenges in maintaining wellbore integrity and preventing CO2 leakage. To address these challenges, a self-healing CO2-resistant cement system was implemented using the Perforate-Wash-Cement (PWC) technique. This system autonomously repairs micro-annuli in the cement sheath, preventing leakage and ensuring long-term containment. The PWC method enables precise casing perforation, annular cleaning, and placement of uncontaminated cement in a single run, effectively restoring the caprock. This integrated approach marks a significant advancement in CCS well integrity. The successful deployment at the project demonstrates its potential for broader industry adoption, contributing to safer and more environmentally responsible CCS operations.