無洩漏風險之二氧化碳地質封存研究

A Numerical Study of Leakproof CO_2 Geological Storage

李元亨(Y.H. Li) ； 沈建豪(C.H. Shen) ； 馬瑋謙(W.C. Ma) ； 林千祺(C.C. Lin) ； 謝秉志(B.Z. Hsieh)

《鑛冶：中國鑛冶工程學會會刊》 63卷2期 (2019/06) Pp. 40-52

https://doi.org/10.30069/MM.201906_63(2).04

摘要

封存安全是二氧化碳地質封存的首要指標。傳統的二氧化碳封存是將超臨界二氧化碳注入，利用構造封存等機制將二氧化碳封存於地層中，在此情境下需要有蓋岩層封阻才更方便將二氧化碳安全封存。本研究的主要目的是追求無洩漏風險的二氧化碳地質封存方法，在二氧化碳注入到鹽水層之前，即在地表或井內將二氧化碳溶解於水中，使二氧化碳在地層內直接以溶解封存機制開始進行封存，可以更快促進礦化反應，使二氧化碳更早固化為礦物相封存。本研究使用數值模擬法，以台灣Y礦區魚藤坪砂岩層為目標場址進行研究。模擬結果顯示以飽和二氧化碳水溶液做為注入流體，可加快二氧化碳團塊消散速度，並大幅增加礦化反應速率，使二氧化碳更快固化為碳酸鹽礦物而永久且安全的封存，達成無洩漏風險之二氧化碳封存目的。

關鍵字

礦化封存 ； 二氧化碳水溶液 ； 封存安全性

並列摘要

The issue of safety is the first priority in carbon dioxide geological storage when injecting CO_2 into saline aquifers. The traditional CO_2 storage method is to inject CO_2 as a supercritical phase fluid into a formation. CO_2 is mainly trapped by the structural seal. The storage needs a sealed caprock to prevent CO_2 from leaking. The purpose of this study was to seek a leakproof CO_2 geological storage. CO_2 was dissolved in water on the ground or in the wellbore before it was injected into a saline aquifer. The solubility trapping mechanism could occur immediately in the storage. The mineralization trapping ensured a safe CO_2 storage. A numerical simulator was used in this study. The target site was the Yutengping sandstone formation in Y-field, which is a potential CO_2 storage formation in Taiwan. The simulation results showed that the geochemical reactions process was fast that accelerated the mineralization speed by means of dissolved CO_2 injection. CO_2 mineralization presented a novel strategy of injecting dissolved CO_2 to provide a leakproof CO_2 storage.

並列關鍵字

Mineralization mechanisms ； Dissolved CO_2 injection ； Storage safety