報告書番号

U00005

タイトル（和文）

高温岩体発電のための貯留層造成技術の開発 --雄勝地点における二段貯留層の造成とその評価--

タイトル（英文）

Development of a reservoir construction methods for Hot Dry Rock Geothermal Power - Two stage reservoir creation and its evaluation at Ogachi -

概要 （図表や脚注は「報告書全文」に掲載しております）

当所で開発した多段貯留層造成手法（ＣＲＳＰ法）を、秋田県雄勝地点の深さ1000ｍで岩盤温度約230℃の坑井（注入井）に適用し、深さ700ｍと1000ｍの２箇所から高温岩体貯留層を造成した。この貯留層の位置や広がりは、ＡＥ観測などにより評価し、貯留層を貫くように生産井を掘削した。そして、貯留層を通して注入井と生産井との間で水を循環し、地下から約165℃の熱水を抽出した。これにより、ＣＲＳＰ法により造成された貯留層が、高温岩体貯留層として利用できることを確認した。しかし、二段の貯留層の進展方向が異なり、循環水の回収率が25％程度と低いことなどから、今後より詳細な貯留層内外の地質構造や熱水流動の解明を図ると共に、多段貯留層からの効率的な熱抽出および寿命評価について検討を進める予定である。

概要 （英文）

By applying the CRSP method which was developed by CRIEPI, a two stage HDR reservoir was created from an injection well which was drilled to a depth of 1000m and the bottom hole temperature was measured around 230 degree C. The reservoir location and dimension were evaluated by the AE method. A production well was drilled to penetrate the reservoir according to the reservoir evaluation results. Some water circulation experiments were conducted between the wells through the reservoir. During these experiments, hot water at 170 degree C was recovered from the underground. The reservoir created by the CRSP method was shown practically useful. However, there are some problems, that is, the fracture progression directions were different each other and water recovery during water circulation was so small as 25 %. Therefore, we will study more ditail geological structure and water flow condition in and around the reservoir. We will also study effective heat extraction and lifetime study of the two-stage reservoir.

報告者

キーワード