摘要 為了控制溫室效應對環境的影響，減少二氧化碳排放量成為近年來全世界都在努力的方向，而二氧化碳捕捉與封存(CCS)的方法已在國際間廣泛使用，其中地質封存的成本最低，尤其在排碳源附近設立二氧化碳捕捉設施並就地封存，最有經濟效益。本研究區域在台灣西北部的觀音地區，鄰近有大潭火力發電廠及鋼鐵工廠、石化工廠等，為主要碳排放源，本研究使用高解析度三維反射震測法來調查桃園科技園區內的CCS預計井址，主要目的在於調查井址的地下構造，以及作為監測二氧化碳灌注後的監測基準。 相較於傳統油工業的震測探勘，高解析度反射震測的探勘範圍較小，探測深度也較淺，但是可以清楚地描繪細部的構造，在淺層的地層分層較為細緻。野外施測部分，本研究使用的震源為震盪震源車(MiniVib)，受波器選用40Hz Geophone，程陣列布置，共放置12條平行線，每條48顆受波器，受波器間距4公尺，線間距16公尺。使用重合方格大小為8*8公尺，可解析範圍約800*600公尺。炸點使用環炸法布置：受波器沿預計井址布置，震盪震源車則圍繞受波器陣列，在桃科園區內道路上施測，使波線完整包覆各個方位角，有良好的資料品質，即使在3000公尺深也可以解析出厚度僅4公尺的地層反射訊號，不僅能夠調查細部的地下構造，還能夠作為二氧化碳灌注後移棲行為的監測。 震測結果與東北方三公里處的中油觀音一號井資料做比對，可以發現(1)錦水頁岩在深度800~1000公尺處，此層孔隙率與滲透率極低，為良好的蓋層，(2)桂竹林層與南莊層深度在1000~1700公尺深，擁有高孔隙率之厚砂岩，適合作為二氧化碳封存的儲集層。故研判本區域擁有良好的蓋層，以及深度適中、孔隙率高的厚層儲集層，為良好的二氧化碳封存場址。此外此區地層由海向陸地傾斜，傾角約2.5度，若在此區實施二氧化碳封存，灌注後二氧化碳推測會往台灣海峽方向移動，可避免對陸上環境造成影響。 ;A 3D Seismic Study around a CCS Drill Site Anstract The reduction of CO2 emission to lessen the global warming has become an important issue in recent years. The capture of CO2 during its manufacturing process in the electric power plant and storing in the adjacent area is considered to be an economical and feasible way. This research uses the 3D high-resolution seismic reflection method to investigate a possible CCS site along the coast in Taiwan. The site is near an electric power plant and is planned to be a CCS experiment laboratory. The main objective is to detect the proper geologic structure and to prepare the baseline data for the future CO2 monitoring. The size of the high-resolution method applied in this study is much smaller than that used in the oil exploration. The obtained high quality and high resolution data can resolve very detailed structures. The Minivibe is used as a source with 576 40Hz-geophones. The bin size is 8m x 8m with an average fold of 30. A surrounding type of 3D data acquisition was taken with sources on the outside roads and receivers fixed around the planned drill site. The structural layer as thin as 4m is able to be detected even under a depth of 3000m. Such a high resolution allows us not only to estimate the structure, but also able to monitor the migration of CO2 after storage. The results of seismic measurement after comparing with a nearby borehole data show that : 1) the caprock is Chinshui shale which is at the depth of 880~1000m, 2) the Nanchuang formation and Kueichulin formation with high porosity can be proper reservoir layers which are located at the depth between 1000m to 1700m. In conclusion, this site has good caprocks, thick reservoirs with high porosity and, most important, at suitable depths. This could be a good CCS site. Very detailed layered structures with dipping angle of 2.3 degrees opposite to the sea direction are revealed. It means that if CO2 are injected in this reservoir, it may migrate toward Taiwan Strait.
