台西盆地南段晚中新世至更新世沉積地層作為碳地質封存層之探討研究

Carbon Dioxide Sequestration Assessment of Late Miocene to Pleistocene Sedimentary Strata in the Southern Flank of the Tai-hsi Basin

10.30069/MM.201103.0010

焦中輝(C. H. Chiao)；林俊余(J. Y. Lin)；俞旗文(C. W. Yu)；盧佳遇(C. Y. Lu)

台西盆地 ； 地質封存 ； 儲集層 ； 蓋層 ； 阻滯層 ； 數值模擬 ； Tai-hsi Basin ； Geological sequestration ； Reservoir ； Cap rock ； Retardation layer ； Numerical simulation

鑛冶：中國鑛冶工程學會會刊

55卷1期（2011 / 03 / 01）

109 - 128

英文

台灣電力公司為推動進行台西盆地CO2地質封存、先導試驗場址地層深鑽與CO2注入之計畫可行性研究，需先評估確認在場址地表下可能的儲集層、蓋層及上覆相關地層及其岩石特性。經參考前人對台西盆地地層剖面歷來研究調查成果，及注入超臨界相態二氧化碳於合適的地下深度範圍，本研究團隊初步擬定了盆地內晚中新世至更新世沉積地層，作為CO2地表下封存層之可行性目標地層，並進行進一步分層探討。目標地層主要包括台灣中部地區桂竹林層、錦水頁岩、卓蘭層與頭嵙山層等四個地層。透過諸多地表露頭剖面、附近地質鑽井與車籠埔斷層深鑽井TCDP-A等文獻蒐集資料，經整合分析研究區域內其岩性與沉積環境特性，將目標地層分為六種具代表性岩性單位，進行儲集層、蓋層與阻滯層之分層判別。並將分層判別結果，進一步結合附近鑽井地質資料及井測結果的對比，完成研究區域內二維、三維地質剖面分層判釋與模型建構。本研究並以場址三維地質模型建構成果，結合數值分析，考慮了13層影響CO2向上移動的分層，配合各層不同孔隙率與滲透率推估參數，以探討阻滯層的存在對移棲結果進行探討。最後，並對未來大規模注入的情境進行模擬，以探討類似地層結構下，以10孔併行注入，年封存CO2量達一千萬公噸之可行性。

Taiwan Power Company is exploring the feasibility of carbon dioxide geo-sequestration. A site screening project identified a deep saline aquifer in the Tai-Hsi Basin as a potential candidate. An extensive literal review and analysis of available geological data indicated that some Miocene to Pleistocene rock Formations including KT, CS, CL, and TK Formations are suitable for the geo-sequestration. We divided the suitable formations into six major lithologic units and further subdivided them into three types of sequestration units including reservoir, cap rock, and retardation layer, based on their sedimentary environment and physical properties. A sophisticate geologic model is thus established and thereby, a numerical simulation model is used to simulate the CO2 geo-sequestration. The numerical simulation considered 13 layers of sequestration related units each with different porosity and permeability. Results show that the existence of retardation layers can significantly hinder the upward migration of the injected plume. Results also showed that 50 years after injection and 30 years after closure of the injection wells, all injected plumes are safely contained within the sequestering layers. Our simulation results also showed the feasibility of a 10-injection-well sequestration scheme that could contain 10 million tons of CO2 per year.