Volume 33: CCUS Technologies for the Carbon Neutrality: Part I

Development status and prospect of natural gas hydrate recovery by CO2 replacement Zhang Zhi, Zhao Yuanjin

Abstract

Using CO2 replacement to extract natural gas hydrates can not only achieve CO2 storage, but also ensure the safety of natural gas hydrate extraction, which is one of the necessary ways to achieve China’s “dual carbon goals”. However, the existing research on CO2 replacement extraction of natural gas hydrates is not yet mature, making it difficult to support large-scale CO2 storage and commercial extraction of natural gas hydrates. Therefore, this article systematically elaborates on the current situation and necessity of CO2 storage, the distribution range and development challenges of natural gas hydrates in China, and analyzes the feasibility and wellbore integrity issues of CO2 replacement extraction of natural gas hydrates. Research has shown that: CO2 emissions are increasing year by year, seriously affecting the living environment of humans and other species, and must be sealed. China is rich in natural gas hydrates, but conventional mining can easily affect the stability of the strata and trigger natural disasters such as submarine landslides. Since single displacement reaction is a spontaneous process and CO2 hydrate sediment intensity is higher, the feasibility of CO2 replacement for natural gas hydrate exploitation is high. It is necessary to focus on the corrosion integrity of the cement and underground tubing during the replacement mining process.

Keywords CCUS, natural gas hydrate, replacement mining, feasibility, corrosion integrity