Validation and Evaluation of an Estimation Method for Deep Thermal Structures Using an Activity Index in Major Geothermal Fields in Northeastern Japan
Validation and Evaluation of an Estimation Method for Deep Thermal Structures Using an Activity Index in Major Geothermal Fields in Northeastern Japan
复制标题
日本东北部主要地热田使用活动指数的深层热结构估算方法的验证和评估
DOI：
10.3390/en13184684
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发表时间：
2020
期刊：
影响因子：
3.2
通讯作者：
H. Asanuma
中科院分区：
文献类型：
--
作者：
Yota Suzuki;H. Muraoka;H. Asanuma
在日本东北部，在距地球表面几公里深处的脆-韧性转变（BDT）带周围存在着相当数量的具有不同比例超临界流体的岩体。由于大陆地壳花岗岩基底中的BDT带估计出现在380 °C左右，因此确定对应于380 °C的深度对于利用“超临界地热系统”内的热能非常重要。在本研究中，我们集中在一个估计方法，以确定对应于380 °C的等温层的深度，使用活动指数（AI）从地热威尔斯和温泉的最高温度数据获得。利用深部热探钻孔的热剖面和天然地震的震源分布，用活动性指数评价了深部热结构的特征和精度。对应380 °C的估计深度往往高于实际深度，最大可能估计误差约为9.7公里。利用本研究的结果，制作了日本东北部6个主要地热田的380 °C等温层深度分布图。
A considerable number of rock bodies with varying percentages of supercritical fluid exist around the brittle–ductile transition (BDT) zone at a depth of several kilometers from the surface of the Earth, in northeastern Japan. As the BDT zone in the granitic basement of the continental crust is estimated to occur at about 380 °C, the identification of the depth corresponding to 380 °C is important to utilize the thermal energy inside the “supercritical geothermal systems”. In this study, we focused on an estimation method to determine the depth of the isothermal layer corresponding to 380 °C, using the activity index (AI) obtained from the maximum-temperature data of the geothermal wells and hot springs. The thermal profiles of deep and hot exploration boreholes and the hypocentral distribution of natural earthquakes were used to evaluate the characteristics and accuracy of the deep thermal structure, using the activity index. The estimated depth corresponding to 380 °C tended to be higher than the actual depth, with a maximum possible estimation error of approximately 9.7 km. Distribution maps showing the depth of the isothermal layer corresponding to 380 °C were created for six major geothermal fields in northeastern Japan, using the results from this study.
影响因子：
2.9
作者：
Omuralieva, Aiymjan M.;Hasegawa, Akira;Okada, Tomomi
通讯作者：
Okada, Tomomi