首页 > 最新文献

Geothermics最新文献

英文 中文
Geothermal resource potential from intraplate magmatic–volcanic activities: A case study of Mt. Changbai in Northeast China 板块内岩浆-火山活动的地热资源潜力:中国东北长白山案例研究
IF 3.9 2区 工程技术 Q1 Earth and Planetary Sciences Pub Date : 2024-06-03 DOI: 10.1016/j.geothermics.2024.103053
Chujie Cheng , Runchao Liu , Hui Wu , Bo Zhang , Jianlei Zheng , Bingrou Peng , Jinjiang Zhang

Mount Changbai is an active volcano in Northeast China that has erupted several times since the Miocene. Investigating the potential high–temperature geothermal reservoirs associated with magma chambers under the volcano has a significant meaning for clean energy development and utilization. Through a geological field survey combined with drilling data and collected geophysical data, including seismic and magnetotelluric data, of the Mt. Changbai area, we constructed a geological model extending from the upper mantle to the surface. Based on the geological model, we performed thermal simulations to understand the evolution of temperature profiles under Mt. Changbai since the Miocene (∼25 Ma). The results were compared with temperature measurements from geothermal drilling and hot springs for validation. We found that: (1) The total temperature increase can reach ∼263 °C at –6 km (absolute depth) under the Mt. Changbai volcano. While the temperature increase has reached ∼224 °C since the shallow magma chamber appeared at ∼1.5 Ma, which accounts for >80 % of the total temperature increase. (2) Surface cold–water infiltration caused the decrease of subsurface temperature. However, the water can result in local accumulation of heat with a temperature increase up to 44 °C. (3) Both hydrothermal and hot dry rock geothermal resources are abundant in the Mt. Changbai area. Sedimentary strata of the Meso–Neoproterozoic and above that have good porosity and permeability, forming hydrothermal reservoirs. The temperature can reach 150 °C at a depth of 3 km under the Tianchi crater and are transferred to the surface by water through faults. While, metamorphic rock of the Archean–Paleoproterozoic and intrusive rock of the Mesozoic can form hot dry rock geothermal reservoirs with a temperature of 200–400 °C at a depth of 4–7 km under the Tianchi crater and surrounding areas.

长白山是中国东北地区的一座活火山,自中新世以来曾多次喷发。研究与火山下岩浆腔相关的潜在高温地热储层对清洁能源的开发利用具有重要意义。通过对长白山地区的实地地质调查,结合钻探数据和收集到的地球物理数据,包括地震和磁电数据,我们构建了一个从上地幔延伸到地表的地质模型。根据该地质模型,我们进行了热模拟,以了解自中新世(25 Ma∼)以来长白山下温度剖面的演变。我们将模拟结果与地热钻探和温泉的温度测量结果进行了对比验证。我们发现(1) 在长白山火山下-6 千米(绝对深度)处,总升温可达 ∼ 263 °C。而自 1.5 Ma ∼ 1.5 Ma 出现浅部岩浆腔以来,温度上升达 224 ℃,占总温度上升的 80%。(2)地表冷水渗透导致地下温度下降。(3) 长白山地区热液地热和干热岩地热资源丰富。中新生代及以上沉积地层具有良好的孔隙度和渗透性,形成热液储层。天池陨石坑下 3 千米深处的温度可达 150 ℃,并通过断层由水转移到地表。而在天池陨石坑及周边地区,奥陶系-古近纪的变质岩和中生代的侵入岩可形成干热岩地热储层,在天池陨石坑及周边地区4-7千米深处的温度可达200-400℃。
{"title":"Geothermal resource potential from intraplate magmatic–volcanic activities: A case study of Mt. Changbai in Northeast China","authors":"Chujie Cheng ,&nbsp;Runchao Liu ,&nbsp;Hui Wu ,&nbsp;Bo Zhang ,&nbsp;Jianlei Zheng ,&nbsp;Bingrou Peng ,&nbsp;Jinjiang Zhang","doi":"10.1016/j.geothermics.2024.103053","DOIUrl":"https://doi.org/10.1016/j.geothermics.2024.103053","url":null,"abstract":"<div><p>Mount Changbai is an active volcano in Northeast China that has erupted several times since the Miocene. Investigating the potential high–temperature geothermal reservoirs associated with magma chambers under the volcano has a significant meaning for clean energy development and utilization. Through a geological field survey combined with drilling data and collected geophysical data, including seismic and magnetotelluric data, of the Mt. Changbai area, we constructed a geological model extending from the upper mantle to the surface. Based on the geological model, we performed thermal simulations to understand the evolution of temperature profiles under Mt. Changbai since the Miocene (∼25 Ma). The results were compared with temperature measurements from geothermal drilling and hot springs for validation. We found that: (1) The total temperature increase can reach ∼263 °C at –6 km (absolute depth) under the Mt. Changbai volcano. While the temperature increase has reached ∼224 °C since the shallow magma chamber appeared at ∼1.5 Ma, which accounts for &gt;80 % of the total temperature increase. (2) Surface cold–water infiltration caused the decrease of subsurface temperature. However, the water can result in local accumulation of heat with a temperature increase up to 44 °C. (3) Both hydrothermal and hot dry rock geothermal resources are abundant in the Mt. Changbai area. Sedimentary strata of the Meso–Neoproterozoic and above that have good porosity and permeability, forming hydrothermal reservoirs. The temperature can reach 150 °C at a depth of 3 km under the Tianchi crater and are transferred to the surface by water through faults. While, metamorphic rock of the Archean–Paleoproterozoic and intrusive rock of the Mesozoic can form hot dry rock geothermal reservoirs with a temperature of 200–400 °C at a depth of 4–7 km under the Tianchi crater and surrounding areas.</p></div>","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141243529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Geothermal resource evaluation of the Middle Permian Qixia-Maokou Formation in the southern Sichuan Basin, China 中国四川盆地南部中二叠统栖霞-庙口地层地热资源评价
IF 3.9 2区 工程技术 Q1 Earth and Planetary Sciences Pub Date : 2024-06-01 DOI: 10.1016/j.geothermics.2024.103073
Yigao Sun , Yinhui Zuo , Luquan Zhang , Chao Zhang , Yingchun Wang , Tao Zhang , Xiao Li , Meihua Yang , Kangnan Yan , Longqing Cui

The southern Sichuan Basin is an abnormal area of high present geothermal fields in the Sichuan Basin. It is a favorable area for the development of geothermal resources in the Sichuan Basin. But its evaluation of geothermal resources is lagging, which has severely affected the development of geothermal resources in the southern Sichuan Basin. In the paper, firstly, based on the temperature data of wells, the geothermal gradients and heat flows of typical wells in the study area were calculated, and the temperatures at the top and bottom of the reservoir in the Qixia-Maokou Formation were calculated using a one-dimensional steady-state heat conduction equation. Then, geothermal resource intensities and reserves of the Middle Permian Qixia-Maokou Formation in the southern Sichuan Basin were evaluated by using a method for rapidly calculating geothermal resources in sedimentary basins by multi-data fusion. Finally, suggestions for geothermal development were proposed. The results show that the geothermal gradient and heat flow values in the southern Sichuan Basin range from 15.6 to 33.70 °C/km and 49 to 85 mW/m2, respectively, and the temperature of the reservoir in the Qixia-Maokou Formation ranges from 50 to 120 °C. The geothermal resources are 3.09 × 1021 J, equivalent to 105 billion tons of standard coal, and the recoverable resources are 6.18 × 1020 J, equivalent to 21 billion tons of standard coal. The development of demonstration projects will focus on the mid- to low-temperature geothermal power generation, geothermal grain drying and geothermal agriculture in the southwestern region of the southern Sichuan Basin. The research results can provide a resource basis for the development of geothermal resources in the southern Sichuan Basin.

四川盆地南部是四川盆地现存地热田较多的异常区。是四川盆地地热资源开发的有利区域。但其地热资源评价滞后,严重影响了四川盆地南部地热资源的开发。本文首先根据井温数据,计算了研究区典型井的地热梯度和热流量,并利用一维稳态导热方程计算了栖霞-庙口地层储层顶部和底部的温度。然后,利用多数据融合快速计算沉积盆地地热资源的方法,评价了四川盆地南部中二叠统栖霞-庙口地层的地热资源强度和储量。最后提出了地热开发建议。结果表明,四川盆地南部的地热梯度和热流值分别为 15.6 至 33.70 ℃/km 和 49 至 85 mW/m2,栖霞-庙口地层的储层温度为 50 至 120 ℃。地热资源量为 3.09×1021 J,相当于 1050 亿吨标准煤,可采资源量为 6.18×1020 J,相当于 210 亿吨标准煤。示范工程的开发重点是四川盆地南部西南地区的中低温地热发电、地热粮食烘干和地热农业。研究成果可为四川盆地南部地热资源开发提供资源基础。
{"title":"Geothermal resource evaluation of the Middle Permian Qixia-Maokou Formation in the southern Sichuan Basin, China","authors":"Yigao Sun ,&nbsp;Yinhui Zuo ,&nbsp;Luquan Zhang ,&nbsp;Chao Zhang ,&nbsp;Yingchun Wang ,&nbsp;Tao Zhang ,&nbsp;Xiao Li ,&nbsp;Meihua Yang ,&nbsp;Kangnan Yan ,&nbsp;Longqing Cui","doi":"10.1016/j.geothermics.2024.103073","DOIUrl":"https://doi.org/10.1016/j.geothermics.2024.103073","url":null,"abstract":"<div><p>The southern Sichuan Basin is an abnormal area of high present geothermal fields in the Sichuan Basin. It is a favorable area for the development of geothermal resources in the Sichuan Basin. But its evaluation of geothermal resources is lagging, which has severely affected the development of geothermal resources in the southern Sichuan Basin. In the paper, firstly, based on the temperature data of wells, the geothermal gradients and heat flows of typical wells in the study area were calculated, and the temperatures at the top and bottom of the reservoir in the Qixia-Maokou Formation were calculated using a one-dimensional steady-state heat conduction equation. Then, geothermal resource intensities and reserves of the Middle Permian Qixia-Maokou Formation in the southern Sichuan Basin were evaluated by using a method for rapidly calculating geothermal resources in sedimentary basins by multi-data fusion. Finally, suggestions for geothermal development were proposed. The results show that the geothermal gradient and heat flow values in the southern Sichuan Basin range from 15.6 to 33.70 °C/km and 49 to 85 mW/m<sup>2</sup>, respectively, and the temperature of the reservoir in the Qixia-Maokou Formation ranges from 50 to 120 °C. The geothermal resources are 3.09 × 10<sup>21</sup> J, equivalent to 105 billion tons of standard coal, and the recoverable resources are 6.18 × 10<sup>20</sup> J, equivalent to 21 billion tons of standard coal. The development of demonstration projects will focus on the mid- to low-temperature geothermal power generation, geothermal grain drying and geothermal agriculture in the southwestern region of the southern Sichuan Basin. The research results can provide a resource basis for the development of geothermal resources in the southern Sichuan Basin.</p></div>","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141243530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
A thermo-hydro-mechanical simulation on the impact of fracture network connectivity on the production performance of a multi-fracture enhanced geothermal system 断裂网连通性对多断裂强化地热系统生产性能影响的热工水力学模拟
IF 3.9 2区 工程技术 Q1 Earth and Planetary Sciences Pub Date : 2024-05-30 DOI: 10.1016/j.geothermics.2024.103070
Zhihong Lei , Yulong Zhang , Xingjie Lin , Yu Shi , Yunhui Zhang , Ling Zhou , Yaping Shen

Connectivity is an inherent feature of heterogeneous hydraulic conductivity fields and determines the paths of least resistance along which fluid fluxes converge in multi-fracture enhanced geothermal systems (EGS). In this work, numerical algorithms are used to construct fractured porous media models to analyze fractures and the rock matrix in EGS systems. Connectivity coefficients are defined to quantify the connectivity of the fractured system. Based on this, the impacts of fracture connectivity, non-connected fractures, and injection-production pressure differences on EGS production performance are investigated. The research results confirm that the connected area ratio (Rs) is an effective indicator of the connectivity level of the fracture network. Fluid flow and heat exchange predominantly take place within the interconnected area of fractures. When Rs = 0, geothermal energy cannot be efficiently extracted, resulting in significant waste of geothermal resources; when 0 < Rs < 0.1, thermal short-circuit easily occurs in the reservoir; then, as Rs continues to increase, the thermal extraction performance improves. The thermal output power increases with the square of Rs. Dead-end and discontinuous fractures improve the reservoir's fluid mobility, but their contribution to fluid flow is limited. In addition, very high fluid mobility in the matrix of the connected zone weakens the ability of fractures to act as flow channels and triggers a premature thermal breakthrough, shortening the EGS's lifespan. Therefore, striking a balance between the reservoir's lifespan and heat extraction capacity requires precise control of the injection-production pressure difference. Developing a 500 × 500 m2 (on a horizontal plane) multi-fracture EGS in deep granite formations, Rs of the fractured zones should be greater than 0.5 to reduce fluid resistance and ensure effective heat extraction. In such a case, it is advisable to maintain a pressure differential of no more than 10 MPa between the injection and production wells to achieve at least 30 years of continuous heat extraction.

连通性是异质水力传导场的固有特征,决定了多断裂强化地热系统(EGS)中流体流汇聚的最小阻力路径。本研究采用数值算法构建断裂多孔介质模型,以分析 EGS 系统中的断裂和岩石基质。定义了连通系数,以量化断裂系统的连通性。在此基础上,研究了裂缝连通性、非连通裂缝以及注入-生产压力差对 EGS 生产性能的影响。研究结果证实,连通面积比(Rs)是衡量裂缝网络连通性水平的有效指标。流体流动和热交换主要发生在断裂的连通区域内。当 Rs = 0 时,地热能不能被有效提取,造成地热资源的严重浪费;当 0 < Rs < 0.1 时,储层中容易发生热短路;然后,随着 Rs 的不断增大,热提取性能得到改善。死端裂缝和不连续裂缝可提高储层的流体流动性,但对流体流动的贡献有限。此外,连通区基质中极高的流体流动性会削弱裂缝作为流动通道的能力,引发过早的热突破,缩短 EGS 的寿命。因此,要在储层寿命和热提取能力之间取得平衡,就必须精确控制注入-生产压差。在深层花岗岩地层开发 500 × 500 平方米(水平面)的多裂缝 EGS 时,裂缝区的 Rs 应大于 0.5,以减少流体阻力,确保有效汲取热量。在这种情况下,最好保持注入井和生产井之间的压差不超过 10 兆帕,以实现至少 30 年的连续采热。
{"title":"A thermo-hydro-mechanical simulation on the impact of fracture network connectivity on the production performance of a multi-fracture enhanced geothermal system","authors":"Zhihong Lei ,&nbsp;Yulong Zhang ,&nbsp;Xingjie Lin ,&nbsp;Yu Shi ,&nbsp;Yunhui Zhang ,&nbsp;Ling Zhou ,&nbsp;Yaping Shen","doi":"10.1016/j.geothermics.2024.103070","DOIUrl":"https://doi.org/10.1016/j.geothermics.2024.103070","url":null,"abstract":"<div><p>Connectivity is an inherent feature of heterogeneous hydraulic conductivity fields and determines the paths of least resistance along which fluid fluxes converge in multi-fracture enhanced geothermal systems (EGS). In this work, numerical algorithms are used to construct fractured porous media models to analyze fractures and the rock matrix in EGS systems. Connectivity coefficients are defined to quantify the connectivity of the fractured system. Based on this, the impacts of fracture connectivity, non-connected fractures, and injection-production pressure differences on EGS production performance are investigated. The research results confirm that the connected area ratio (<em>R<sub>s</sub></em>) is an effective indicator of the connectivity level of the fracture network. Fluid flow and heat exchange predominantly take place within the interconnected area of fractures. When <em>R<sub>s</sub></em> = 0, geothermal energy cannot be efficiently extracted, resulting in significant waste of geothermal resources; when 0 &lt; <em>R<sub>s</sub></em> &lt; 0.1, thermal short-circuit easily occurs in the reservoir; then, as <em>R<sub>s</sub></em> continues to increase, the thermal extraction performance improves. The thermal output power increases with the square of <em>R<sub>s</sub></em>. Dead-end and discontinuous fractures improve the reservoir's fluid mobility, but their contribution to fluid flow is limited. In addition, very high fluid mobility in the matrix of the connected zone weakens the ability of fractures to act as flow channels and triggers a premature thermal breakthrough, shortening the EGS's lifespan. Therefore, striking a balance between the reservoir's lifespan and heat extraction capacity requires precise control of the injection-production pressure difference. Developing a 500 × 500 m<sup>2</sup> (on a horizontal plane) multi-fracture EGS in deep granite formations, <em>R<sub>s</sub></em> of the fractured zones should be greater than 0.5 to reduce fluid resistance and ensure effective heat extraction. In such a case, it is advisable to maintain a pressure differential of no more than 10 MPa between the injection and production wells to achieve at least 30 years of continuous heat extraction.</p></div>","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141243511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Experimental and numerical investigations on thermo-mechanical behaviors of energy pile group under different operational strategies 不同运行策略下能源桩群热力学行为的实验和数值研究
IF 3.9 2区 工程技术 Q1 Earth and Planetary Sciences Pub Date : 2024-05-29 DOI: 10.1016/j.geothermics.2024.103072
Weibo Yang, Chengrong Wang, Chaoyi Yan, Feng Wang

Energy piles are often operated in the form of pile group, and their thermo-mechanical (TM) behaviors are strongly affected by the operational strategies. A model experimental bench of energy pile group with the layout of 3 × 3 was established to investigate the TM behaviors of energy pile group under different start-stop time ratios and pipe connection forms. The test results show that under the current test conditions, raising the start-stop time ratio leads to the increase of heat storage and extraction amount by the pile group, but the temperature of soil around the pile is not well recovered, which in turn results in the rise of deformation degree of pile. For the connection forms of pile buried pipe, the heat storage amount under three kinds of series connection forms is less than that under the conventional parallel connection form. However, the mechanical properties of pile group under the series connection forms are better than those of parallel connection form, which helps to alleviate the pile deformation degree. A 4 × 4 group pile model was developed to further find the effects of two operation strategies, namely, opening partial piles at different locations in winter mode and non-uniform intensity operation of piles in the inner and outer zones, on the TM characteristics of energy pile group. The results showed that opening partial piles increased the axial force of pile in the running piles relative to opening all the piles. Meanwhile, opening eight side piles extracted more heat per month during the heat extraction period relative to opening four internal piles and four corner piles. The four kinds of internal and external zoned non-uniform strength operation modes have different energy storage and thermodynamic properties. The most suitable mode should be selected considering the actual situation.

能源桩通常以桩群形式运行,其热力学(TM)行为受运行策略的影响很大。为研究不同启停时间比和管道连接形式下能源桩群的热力学行为,建立了布局为 3 × 3 的能源桩群模型试验台。试验结果表明,在目前的试验条件下,提高启停时间比会导致桩群蓄热和取热量的增加,但桩周围土体的温度并没有得到很好的恢复,进而导致桩的变形程度增加。对于桩埋管的连接形式,三种串联形式下的蓄热量均小于传统的并联形式。但串联形式下的桩群力学性能优于并联形式,有助于减轻桩的变形程度。建立了一个 4 × 4 群桩模型,以进一步发现两种操作策略(即冬季模式下在不同位置打开部分桩和内外区桩的非均匀强度操作)对能源桩群 TM 特性的影响。结果表明,与全部打桩相比,部分打桩增加了运行中的桩的轴向力。同时,在汲取热量期间,打八根边桩比打四根内桩和四根角桩每月汲取更多的热量。四种内外分区非均匀强度运行模式具有不同的储能和热力学特性。应根据实际情况选择最合适的模式。
{"title":"Experimental and numerical investigations on thermo-mechanical behaviors of energy pile group under different operational strategies","authors":"Weibo Yang,&nbsp;Chengrong Wang,&nbsp;Chaoyi Yan,&nbsp;Feng Wang","doi":"10.1016/j.geothermics.2024.103072","DOIUrl":"https://doi.org/10.1016/j.geothermics.2024.103072","url":null,"abstract":"<div><p>Energy piles are often operated in the form of pile group, and their thermo-mechanical (TM) behaviors are strongly affected by the operational strategies. A model experimental bench of energy pile group with the layout of 3 × 3 was established to investigate the TM behaviors of energy pile group under different start-stop time ratios and pipe connection forms. The test results show that under the current test conditions, raising the start-stop time ratio leads to the increase of heat storage and extraction amount by the pile group, but the temperature of soil around the pile is not well recovered, which in turn results in the rise of deformation degree of pile. For the connection forms of pile buried pipe, the heat storage amount under three kinds of series connection forms is less than that under the conventional parallel connection form. However, the mechanical properties of pile group under the series connection forms are better than those of parallel connection form, which helps to alleviate the pile deformation degree. A 4 × 4 group pile model was developed to further find the effects of two operation strategies, namely, opening partial piles at different locations in winter mode and non-uniform intensity operation of piles in the inner and outer zones, on the TM characteristics of energy pile group. The results showed that opening partial piles increased the axial force of pile in the running piles relative to opening all the piles. Meanwhile, opening eight side piles extracted more heat per month during the heat extraction period relative to opening four internal piles and four corner piles. The four kinds of internal and external zoned non-uniform strength operation modes have different energy storage and thermodynamic properties. The most suitable mode should be selected considering the actual situation.</p></div>","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141243510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Temperature transient analysis: Static formation temperature test (SFTT) an overview 温度瞬态分析:静态形成温度测试 (SFTT) 概述
IF 3.9 2区 工程技术 Q1 Earth and Planetary Sciences Pub Date : 2024-05-25 DOI: 10.1016/j.geothermics.2024.103058
Jorge Alberto Rangel-Arista, Sadiq J. Zarrouk, Eylem Kaya

When drilling a geothermal well, obtaining real-time measurements of the static formation temperature is impractical due to the cooling effect of drilling fluids on the surrounding rock, which masks the actual reservoir temperatures. To overcome this, the site engineers undertake a static formation temperature test (SFTT) to ascertain the stable reservoir temperature. The present work reviews existing methods for analysing data using five different temperature sets sourced from published literature. Based on our analysis, we provide recommendations on the application of the various analytical techniques. We recommend utilising the spherical method when using bottom-hole data, whilst, for any other depth, we recommend one of the cylindrical methods. These recommendations aim to enhance the accuracy and reliability of SFTT assessments during geothermal well drilling operations.

在钻探地热井时,由于钻井液对周围岩石的冷却作用会掩盖实际的储层温度,因此实时测量静态地层温度是不切实际的。为了克服这一问题,现场工程师会进行静态地层温度测试(SFTT),以确定稳定的储层温度。本工作回顾了现有的数据分析方法,使用了从已发表文献中获取的五种不同的温度集。根据分析结果,我们对各种分析技术的应用提出了建议。我们建议在使用井底数据时使用球形方法,而对于其他深度的数据,我们建议使用圆柱形方法中的一种。这些建议旨在提高地热井钻探过程中 SFTT 评估的准确性和可靠性。
{"title":"Temperature transient analysis: Static formation temperature test (SFTT) an overview","authors":"Jorge Alberto Rangel-Arista,&nbsp;Sadiq J. Zarrouk,&nbsp;Eylem Kaya","doi":"10.1016/j.geothermics.2024.103058","DOIUrl":"https://doi.org/10.1016/j.geothermics.2024.103058","url":null,"abstract":"<div><p>When drilling a geothermal well, obtaining real-time measurements of the static formation temperature is impractical due to the cooling effect of drilling fluids on the surrounding rock, which masks the actual reservoir temperatures. To overcome this, the site engineers undertake a static formation temperature test (SFTT) to ascertain the stable reservoir temperature. The present work reviews existing methods for analysing data using five different temperature sets sourced from published literature. Based on our analysis, we provide recommendations on the application of the various analytical techniques. We recommend utilising the spherical method when using bottom-hole data, whilst, for any other depth, we recommend one of the cylindrical methods. These recommendations aim to enhance the accuracy and reliability of SFTT assessments during geothermal well drilling operations.</p></div>","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0375650524001470/pdfft?md5=2a55dd822ab84fc1427b7d7f8b13a2ac&pid=1-s2.0-S0375650524001470-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141095048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Assessment of two recent hot dry rock thermal energy production projects 对最近两个干热岩热能生产项目的评估
IF 3.9 2区 工程技术 Q1 Earth and Planetary Sciences Pub Date : 2024-05-25 DOI: 10.1016/j.geothermics.2024.103051
Balnur Mindygaliyeva, Ozan Uzun, Kaveh Amini, Hossein Kazemi, William Fleckenstein

In this paper, we present analyses of laboratory and field data indicating that the current two-well, injection-production system, connected with multiple hydraulic fractures, is a very promising method for extracting heat from hot dry rock (HDR) systems to generate electricity. The current two-well system could be expanded to a three-well system consisting of one injection well and two symmetric producing wells connected via the central hydraulic fracture emanating from the injection well. To improve a uniform distribution of the injected fluid among all hydraulic fracture stages in the injection well, we advocate for field implementation of a newly designed well stimulation technique, the GeoThermOPTIMAL.

We first present an analysis of the post-fracturing flow data obtained from an HDR geothermal injection well at the Utah FORGE Enhanced Geothermal System (EGS) research field site. The site is adjacent to the Roosevelt hydrothermal (HT) field. The objective of the study is to assess the effectiveness of well stimulation in extracting heat from the low-permeability, hot dry granitoid rock in the Utah FORGE research site. The study includes interpreting pressure falloff data obtained during the well stimulation process and employing laboratory-measured core data as a major input in the interpretation of the field falloff data. As a confirmation of the robustness of our analysis in Utah FORGE, we reviewed and analyzed the flow test results published for an injection-production doublet at the Blue Mountain EGS (Project Red) commercial site in Nevada. From the analyses of these two field tests, we have concluded that the interpretation and findings of the Blue Mountain EGS pilot test are consistent with the interpretation and findings from the Utah FORGE field research project test results.

In summary, our engineering assessments began with laboratory experiments conducted on various core samples, including those from a granite outcrop and the Utah FORGE geothermal reservoir. These experiments aimed to measure key parameters such as matrix and fracture permeabilities, and porosities (km1018m2, kf,eff1015m2,ϕm101,andϕf104). These data served as guides and inputs for analytical and numerical solut

在本文中,我们对实验室和现场数据进行了分析,结果表明,目前由多条水力裂缝连接的双井注采系统是一种非常有前途的从干热岩(HDR)系统中提取热量进行发电的方法。目前的双井系统可扩展为三井系统,包括一口注水井和两口对称的生产井,通过从注水井喷出的中央水力裂缝相连接。为了改善注入流体在注入井中所有水力压裂段之间的均匀分布,我们主张在现场采用一种新设计的油井刺激技术--GeoThermOPTIMAL。我们首先对犹他州 FORGE 强化地热系统(EGS)研究现场的一口 HDR 地热注入井获得的压裂后流动数据进行了分析。该现场毗邻罗斯福热液(HT)场。这项研究的目的是评估从犹他州 FORGE 研究场址的低渗透、干热花岗岩岩石中提取热量的井刺激效果。研究包括解释在油井刺激过程中获得的压力下降数据,并将实验室测量的岩心数据作为解释现场下降数据的主要输入。为了证实我们在 Utah FORGE 中进行的分析的稳健性,我们审查并分析了内华达州蓝山 EGS(红色项目)商业站点的注采双井公布的流量测试结果。通过对这两项实地测试的分析,我们得出结论,蓝山 EGS 试点测试的解释和结论与犹他 FORGE 实地研究项目测试结果的解释和结论是一致的。总之,我们的工程评估始于对各种岩芯样本进行的实验室实验,包括来自花岗岩露头和犹他 FORGE 地热储层的岩芯样本。这些实验旨在测量基质和裂缝渗透率以及孔隙度(km≈10-18m2、kf,eff≈10-15m2、jm≈10-1 和 jf≈10-4)等关键参数。这些数据可作为分析和数值解决方案的指南和输入,用于匹配地热井的现场压力响应。虽然我们没有蓝山 EGS 井的岩心样本,但我们成功地将犹他 FORGE 分析方法应用于蓝山矿址,并持谨慎乐观的态度。
{"title":"Assessment of two recent hot dry rock thermal energy production projects","authors":"Balnur Mindygaliyeva,&nbsp;Ozan Uzun,&nbsp;Kaveh Amini,&nbsp;Hossein Kazemi,&nbsp;William Fleckenstein","doi":"10.1016/j.geothermics.2024.103051","DOIUrl":"https://doi.org/10.1016/j.geothermics.2024.103051","url":null,"abstract":"<div><p>In this paper, we present analyses of laboratory and field data indicating that the current two-well, injection-production system, connected with multiple hydraulic fractures, is a very promising method for extracting heat from hot dry rock (HDR) systems to generate electricity. The current two-well system could be expanded to a three-well system consisting of one injection well and two symmetric producing wells connected via the central hydraulic fracture emanating from the injection well. To improve a uniform distribution of the injected fluid among all hydraulic fracture stages in the injection well, we advocate for field implementation of a newly designed well stimulation technique, the GeoThermOPTIMAL.</p><p>We first present an analysis of the post-fracturing flow data obtained from an HDR geothermal injection well at the Utah FORGE Enhanced Geothermal System (EGS) research field site. The site is adjacent to the Roosevelt hydrothermal (HT) field. The objective of the study is to assess the effectiveness of well stimulation in extracting heat from the low-permeability, hot dry granitoid rock in the Utah FORGE research site. The study includes interpreting pressure falloff data obtained during the well stimulation process and employing laboratory-measured core data as a major input in the interpretation of the field falloff data. As a confirmation of the robustness of our analysis in Utah FORGE, we reviewed and analyzed the flow test results published for an injection-production doublet at the Blue Mountain EGS (Project Red) commercial site in Nevada. From the analyses of these two field tests, we have concluded that the interpretation and findings of the Blue Mountain EGS pilot test are consistent with the interpretation and findings from the Utah FORGE field research project test results.</p><p>In summary, our engineering assessments began with laboratory experiments conducted on various core samples, including those from a granite outcrop and the Utah FORGE geothermal reservoir. These experiments aimed to measure key parameters such as matrix and fracture permeabilities, and porosities (<span><math><mrow><msub><mi>k</mi><mi>m</mi></msub><mo>≈</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>18</mn></mrow></msup><mspace></mspace><msup><mrow><mi>m</mi></mrow><mn>2</mn></msup></mrow></math></span>, <span><math><mrow><msub><mi>k</mi><mrow><mi>f</mi><mo>,</mo><mi>e</mi><mi>f</mi><mi>f</mi></mrow></msub><mo>≈</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>15</mn></mrow></msup><msup><mrow><mi>m</mi></mrow><mn>2</mn></msup><mo>,</mo><mspace></mspace><msub><mi>ϕ</mi><mi>m</mi></msub><mo>≈</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup><mo>,</mo><mspace></mspace><mtext>and</mtext><mspace></mspace><msub><mi>ϕ</mi><mi>f</mi></msub><mo>≈</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>4</mn></mrow></msup></mrow></math></span>). These data served as guides and inputs for analytical and numerical solut","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141097766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Geology of the Utah Frontier Observatory for Research in Geothermal Energy (FORGE) Enhanced Geothermal System (EGS) Site 犹他州地热能研究前沿观测站 (FORGE) 强化地热系统 (EGS) 站点的地质情况
IF 3.9 2区 工程技术 Q1 Earth and Planetary Sciences Pub Date : 2024-05-25 DOI: 10.1016/j.geothermics.2024.103054
Clay Jones, Stuart Simmons, Joseph Moore

The Utah FORGE field-scale laboratory was established to advance and accelerate development of Enhanced Geothermal System (EGS) resources, and this report provides an update on the geological understanding of the EGS reservoir. The succession of rock types intersected by deep wells beneath the site comprise sedimentary basin fill strata and underlying crystalline basement rocks made of: 1) sheared rhyolite; 2) sheared granitoid; 3) granitoid; and 4) interfingered metamorphic and granitoid. Within the intervals dominated by granitoid, igneous rock compositions range from granite to diorite. Below ∼2300 m, metamorphic rocks are primarily made of orthogneisses, with minor marble, quartzite, and schist engulfed by granitoid. Determining the distribution of granitoid and orthogneiss is complicated by similarities in mineralogy (quartz, plagioclase, K-feldspar, biotite, titanite, hornblende) and log responses, as well as the lack of macroscopic textures in cuttings, whereas metasedimentary rocks are more readily recognizable due to their distinctive mineralogies. The uplift and exhumation of the Mineral Mountains batholith induced early plastic deformation represented by subtle foliation of granitoids, the development of penetrative fabrics, and development of narrow mylonite zones. Overprinting by later brittle deformation involved shearing, alteration, and veining, which are most intense at the top of basement and diminish with increasing depth. The distribution of fractures in the EGS reservoir is heterogeneous, and localized intervals of intense fracturing developed along the contacts between granitoids and metamorphic rocks. Secondary minerals (clay minerals and Mg- and Fe-carbonates; minor epidote, actinolite, albite and quartz; trace anhydrite and halite) comprising open-space fillings and replacement of precursor phases tend to be concentrated in fracture zones, with paragenetic relationships reflecting cooling over time.

犹他州 FORGE 野外规模实验室的建立是为了推进和加快强化地热系统(EGS)资源的开发,本报告提供了对强化地热系统储层地质认识的最新情况。现场地下深井所穿透的岩层类型包括沉积盆地填充地层和由以下成分构成的结晶基底岩:1)剪切流纹岩;2)剪切花岗岩;3)花岗岩;4)变质岩和花岗岩交错。在以花岗岩为主的区间内,火成岩的成分从花岗岩到闪长岩不等。在海拔 2300 米以下,变质岩主要由正长片麻岩组成,少量大理岩、石英岩和片岩被花岗岩吞噬。由于矿物学(石英、斜长石、钾长石、黑云母、榍石、角闪石)和测井反应的相似性,以及切屑中缺乏宏观纹理,确定花岗岩和正长片麻岩的分布变得复杂,而变质岩由于其独特的矿物学更容易识别。矿山浴成岩的隆起和掘起诱发了早期塑性变形,表现为花岗岩的细微褶皱、穿透性构造的形成以及狭窄的麦饭石带的发育。后期的脆性变形包括剪切、蚀变和脉状变形,这些变形在基底顶部最为强烈,并随着深度的增加而减弱。EGS 储层中的断裂分布不均匀,沿花岗岩和变质岩之间的接触形成了局部的密集断裂带。次生矿物(粘土矿物、镁碳酸盐和铁碳酸盐;少量表土、阳起石、白云石和石英;微量无水石膏和海绿石)包括空隙填充和前生相的置换,往往集中在断裂带,其副成因关系反映了随着时间的推移而冷却。
{"title":"Geology of the Utah Frontier Observatory for Research in Geothermal Energy (FORGE) Enhanced Geothermal System (EGS) Site","authors":"Clay Jones,&nbsp;Stuart Simmons,&nbsp;Joseph Moore","doi":"10.1016/j.geothermics.2024.103054","DOIUrl":"https://doi.org/10.1016/j.geothermics.2024.103054","url":null,"abstract":"<div><p>The Utah FORGE field-scale laboratory was established to advance and accelerate development of Enhanced Geothermal System (EGS) resources, and this report provides an update on the geological understanding of the EGS reservoir. The succession of rock types intersected by deep wells beneath the site comprise sedimentary basin fill strata and underlying crystalline basement rocks made of: 1) sheared rhyolite; 2) sheared granitoid; 3) granitoid; and 4) interfingered metamorphic and granitoid. Within the intervals dominated by granitoid, igneous rock compositions range from granite to diorite. Below ∼2300 m, metamorphic rocks are primarily made of orthogneisses, with minor marble, quartzite, and schist engulfed by granitoid. Determining the distribution of granitoid and orthogneiss is complicated by similarities in mineralogy (quartz, plagioclase, K-feldspar, biotite, titanite, hornblende) and log responses, as well as the lack of macroscopic textures in cuttings, whereas metasedimentary rocks are more readily recognizable due to their distinctive mineralogies. The uplift and exhumation of the Mineral Mountains batholith induced early plastic deformation represented by subtle foliation of granitoids, the development of penetrative fabrics, and development of narrow mylonite zones. Overprinting by later brittle deformation involved shearing, alteration, and veining, which are most intense at the top of basement and diminish with increasing depth. The distribution of fractures in the EGS reservoir is heterogeneous, and localized intervals of intense fracturing developed along the contacts between granitoids and metamorphic rocks. Secondary minerals (clay minerals and Mg- and Fe-carbonates; minor epidote, actinolite, albite and quartz; trace anhydrite and halite) comprising open-space fillings and replacement of precursor phases tend to be concentrated in fracture zones, with paragenetic relationships reflecting cooling over time.</p></div>","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0375650524001433/pdfft?md5=d6f82242e948fa07a8bc5f3d3aeae1ff&pid=1-s2.0-S0375650524001433-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141097807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Relationship of geothermal surface manifestations with the geology of northeastern Mexico, according to the interpretation of magnetic, gravimetric, and electrical resistivity data 根据对磁力、重力和电阻率数据的解释,地热表面表现与墨西哥东北部地质的关系
IF 3.9 2区 工程技术 Q1 Earth and Planetary Sciences Pub Date : 2024-05-24 DOI: 10.1016/j.geothermics.2024.103059
José Alberto Batista-Rodríguez, Ramón Yosvanis Batista-Cruz, Yuri Almaguer-Carmenates, Felipe de Jesús López-Saucedo, Janet Tolentino-Álvarez

We present geophysics data analysis from northeastern Mexico in areas with superficial geothermal manifestations. We interpreted magnetic anomalies reduced to the pole, gravimetric anomalies, and 2D electrical resistivity tomography models. The results show that the superficial geothermal manifestations are associated with deep or shallow faults in NW-SE and NE-SW directions. These faults may be the main outlet conduits for thermal fluids to the surface and their dynamic activity may constitute a great heat source for the fluids. This heat can also be associated with the cooling of igneous rocks and the radioactive decay of geological materials.

我们介绍了墨西哥东北部有浅层地热现象地区的地球物理数据分析。我们解释了向极点缩小的磁异常、重力异常和二维电阻率层析模型。结果表明,表层地热现象与西北-东南和东北-西南方向的深层或浅层断层有关。这些断层可能是热流体流向地表的主要出口通道,其动态活动可能构成流体的巨大热源。这种热量还可能与火成岩的冷却和地质材料的放射性衰变有关。
{"title":"Relationship of geothermal surface manifestations with the geology of northeastern Mexico, according to the interpretation of magnetic, gravimetric, and electrical resistivity data","authors":"José Alberto Batista-Rodríguez,&nbsp;Ramón Yosvanis Batista-Cruz,&nbsp;Yuri Almaguer-Carmenates,&nbsp;Felipe de Jesús López-Saucedo,&nbsp;Janet Tolentino-Álvarez","doi":"10.1016/j.geothermics.2024.103059","DOIUrl":"https://doi.org/10.1016/j.geothermics.2024.103059","url":null,"abstract":"<div><p>We present geophysics data analysis from northeastern Mexico in areas with superficial geothermal manifestations. We interpreted magnetic anomalies reduced to the pole, gravimetric anomalies, and 2D electrical resistivity tomography models. The results show that the superficial geothermal manifestations are associated with deep or shallow faults in NW-SE and NE-SW directions. These faults may be the main outlet conduits for thermal fluids to the surface and their dynamic activity may constitute a great heat source for the fluids. This heat can also be associated with the cooling of igneous rocks and the radioactive decay of geological materials.</p></div>","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141095047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Isotope geochemical study of carbonate formation in the 84N-3t well in the Oku-Aizu geothermal area: Natural analog study of fluid origin during caprock formation 奥会津地热区 84N-3t 井碳酸盐形成的同位素地球化学研究:岩层形成过程中流体来源的自然模拟研究
IF 3.9 2区 工程技术 Q1 Earth and Planetary Sciences Pub Date : 2024-05-24 DOI: 10.1016/j.geothermics.2024.103061
Dongyang Mao , Jing Zhang , Akira Ueda , Yukiko Hoshino , Ryosuke Oochi , Kensuke Matsumoto , Hisae Kaneko , Amane Terai

In Japan, a method of power generation is under consideration, which involves the injection of supercritical CO2, serving as a heat transfer fluid, into high-temperature geothermal reservoirs to extract thermal energy from the subsurface. During this process, it is anticipated that some of the CO2 will dissolve in the reservoir fluid and react with the surrounding rocks, leading to the precipitation of carbonates and clay minerals. As part of a natural analog study, we investigated the origin of the fluid and carbon that formed the carbonate minerals by analyzing the carbon content and isotope composition of rocks in the 84N-3t well, which is drilled at the Yanaizu-Nishiyama geothermal power plant in Oku-Aizu. Using the results and downhole temperature data, we estimated the oxygen isotope composition of the fluid and carbon isotope composition of HCO3 and CO2 in the fluid. The carbon content in the rocks increased sharply in the depth interval from 400 to 900 m, which was attributed to the precipitation of large amounts of carbonate minerals. The origin of the fluid responsible for the precipitation of the carbonate minerals was determined to be a mixture of meteoric water and fossil seawater at a depth of <400 m and a mixture of magmatic fluid and fossil seawater at deeper levels. The carbon content originated from organic sources in the shallow part at a depth of <900 m and from magmatic CO2 in the deep part. Based on these results, the depth interval from 400 to 900 m was identified as the caprock and the formation temperature of the caprock layer was estimated to be 90−150 °C. Carbonate minerals were also detected at depths of >900 m but in lower amounts. This suggests that when supercritical CO2 is injected into the subsurface from an injection well, some CO2 is fixed as carbonate minerals in shallow depths where the temperature is relatively low, forming an artificial caprock.

日本正在考虑一种发电方法,即向高温地热储层注入作为传热流体的超临界二氧化碳,从地下提取热能。在此过程中,预计部分二氧化碳将溶解在储层流体中,并与周围岩石发生反应,导致碳酸盐和粘土矿物沉淀。作为自然模拟研究的一部分,我们通过分析奥会津八名津西山地热发电站 84N-3t 井中岩石的碳含量和同位素组成,调查了形成碳酸盐矿物的流体和碳的来源。利用这些结果和井下温度数据,我们估算了流体的氧同位素组成以及流体中 HCO3- 和 CO2 的碳同位素组成。岩石中的碳含量在 400 至 900 米的深度范围内急剧增加,这归因于大量碳酸盐矿物的沉淀。据测定,碳酸盐矿物沉淀的流体来源在 400 米深处是陨石水和化石海水的混合物,而在更深处则是岩浆流体和化石海水的混合物。碳含量在深度为 900 米的浅层来自有机来源,在深层来自岩浆二氧化碳。根据这些结果,400 至 900 米的深度区间被确定为盖层,盖层的形成温度估计为 90-150 °C。在 >900 米深处也检测到了碳酸盐矿物,但数量较少。这表明,当超临界二氧化碳从注入井注入地下时,部分二氧化碳在温度相对较低的浅层被固定为碳酸盐矿物,形成人工盖岩。
{"title":"Isotope geochemical study of carbonate formation in the 84N-3t well in the Oku-Aizu geothermal area: Natural analog study of fluid origin during caprock formation","authors":"Dongyang Mao ,&nbsp;Jing Zhang ,&nbsp;Akira Ueda ,&nbsp;Yukiko Hoshino ,&nbsp;Ryosuke Oochi ,&nbsp;Kensuke Matsumoto ,&nbsp;Hisae Kaneko ,&nbsp;Amane Terai","doi":"10.1016/j.geothermics.2024.103061","DOIUrl":"https://doi.org/10.1016/j.geothermics.2024.103061","url":null,"abstract":"<div><p>In Japan, a method of power generation is under consideration, which involves the injection of supercritical CO<sub>2</sub>, serving as a heat transfer fluid, into high-temperature geothermal reservoirs to extract thermal energy from the subsurface. During this process, it is anticipated that some of the CO<sub>2</sub> will dissolve in the reservoir fluid and react with the surrounding rocks, leading to the precipitation of carbonates and clay minerals. As part of a natural analog study, we investigated the origin of the fluid and carbon that formed the carbonate minerals by analyzing the carbon content and isotope composition of rocks in the 84N-3t well, which is drilled at the Yanaizu-Nishiyama geothermal power plant in Oku-Aizu. Using the results and downhole temperature data, we estimated the oxygen isotope composition of the fluid and carbon isotope composition of HCO<sub>3</sub><sup>−</sup> and CO<sub>2</sub> in the fluid. The carbon content in the rocks increased sharply in the depth interval from 400 to 900 m, which was attributed to the precipitation of large amounts of carbonate minerals. The origin of the fluid responsible for the precipitation of the carbonate minerals was determined to be a mixture of meteoric water and fossil seawater at a depth of &lt;400 m and a mixture of magmatic fluid and fossil seawater at deeper levels. The carbon content originated from organic sources in the shallow part at a depth of &lt;900 m and from magmatic CO<sub>2</sub> in the deep part. Based on these results, the depth interval from 400 to 900 m was identified as the caprock and the formation temperature of the caprock layer was estimated to be 90−150 °C. Carbonate minerals were also detected at depths of &gt;900 m but in lower amounts. This suggests that when supercritical CO<sub>2</sub> is injected into the subsurface from an injection well, some CO<sub>2</sub> is fixed as carbonate minerals in shallow depths where the temperature is relatively low, forming an artificial caprock.</p></div>","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141095046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Study on the influence of a single fracture on the performance of backfill heat exchangers in underground stopes 研究单一断裂对地下水井回填热交换器性能的影响
IF 3.9 2区 工程技术 Q1 Earth and Planetary Sciences Pub Date : 2024-05-21 DOI: 10.1016/j.geothermics.2024.103056
Bo Zhang, Wenxuan Zhang, Rui Zhan, Lang Liu, Chao Huan, Yujiao Zhao, Xiaoyan Zhang

Thermal hazards in deep mines can be mined synergistically with the deposit as associated geothermal energy resources. Backfill heat exchangers (BFHEs) as a combination of mine backfilling and ground heat exchanger technology are one of the effective methods to realize ore deposit-geothermal energy synergy mining. However, in the complex environment of deep mines, BFHEs will inevitably suffer from fracture damage during long-term heat storage/release cycle operation, which will affect their working performance. To address this problem, this paper established a scaled-down experimental setup for fractured BFHEs units, and used the experimental data to verify the accuracy of the established three-dimensional transient heat transfer mathematical model of the BFHEs unit. Numerical simulation methods were used to investigate the effects of the position, aperture and fractured depth of a single fracture on the heat extraction performance of the BFHEs unit under fully dry or fully saturated working conditions. Significant differences were found in the effect of different fracture positions on the heat extraction capacity of the BFHEs unit. The extraction of geothermal heat by the BFHEs unit was favored when it was in the middle of two tubes, while the opposite was true for other positions. The effect of fracture on the heat extraction capacity of the BFHEs unit increased linearly with fracture aperture. The effect of the fractured depth was relatively greater in the 1/2–3/4 Hb range. The presence of groundwater significantly reduced the effect of the fracture. The effect of the fracture on the heat extraction capacity of the BFHEs unit was reduced by more than 80 % by changing the operating conditions from fully dry to fully saturated condition. The overall effect of a fracture on the heat extraction capacity of the BFHEs unit was not significant, with a 5 mm wide fracture having an effect of no more than 2.5 %, even under the fully dry condition. However, there was a combined effect of multiple fractures, and for a deposit size of 900 × 7 × 80 m, ten 2 mm apertures fractures would results in a maximum reduction of geothermal extraction from BFHEs by 8527 GJ in 10 years, which was equivalent to the heat load of a 13,753 m2 building for one winter in the cold climate of China.

深部矿井中的热害可作为伴生地热能资源与矿床协同开采。回填换热器(BFHE)作为矿山回填与地热换热技术的结合体,是实现矿床与地热能协同开采的有效方法之一。然而,在深部矿井的复杂环境中,地埋热交换器在长期的蓄热/放热循环运行过程中,不可避免地会出现断裂损伤,影响其工作性能。针对这一问题,本文建立了断裂 BFHEs 装置的缩比实验装置,并利用实验数据验证了所建立的 BFHEs 装置三维瞬态传热数学模型的准确性。利用数值模拟方法研究了在完全干燥或完全饱和工况下,单个裂缝的位置、孔径和裂缝深度对 BFHEs 装置萃取热量性能的影响。结果表明,不同断裂位置对 BFHEs 装置汲取热量能力的影响存在显著差异。当 BFHEs 位于两根管子的中间时,BFHEs 设备有利于提取地热,而其他位置则相反。断裂对 BFHEs 单元汲取热量能力的影响随断裂孔径的增加而线性增加。在 1/2-3/4 Hb 范围内,断裂深度的影响相对较大。地下水的存在明显降低了断裂的影响。将工作条件从完全干燥状态改为完全饱和状态后,断裂对 BFHEs 装置汲取热量能力的影响降低了 80% 以上。即使在完全干燥的条件下,断裂对 BFHEs 设备汲取热量能力的总体影响也不大,5 毫米宽的断裂影响不超过 2.5%。然而,多条断裂会产生综合影响,对于 900 × 7 × 80 米的矿床大小,10 条 2 毫米孔径的断裂会导致 10 年内从 BFHEs 提取的地热最多减少 8527 千兆焦耳,这相当于 13 753 平方米的建筑物在中国寒冷气候下一个冬季的热负荷。
{"title":"Study on the influence of a single fracture on the performance of backfill heat exchangers in underground stopes","authors":"Bo Zhang,&nbsp;Wenxuan Zhang,&nbsp;Rui Zhan,&nbsp;Lang Liu,&nbsp;Chao Huan,&nbsp;Yujiao Zhao,&nbsp;Xiaoyan Zhang","doi":"10.1016/j.geothermics.2024.103056","DOIUrl":"https://doi.org/10.1016/j.geothermics.2024.103056","url":null,"abstract":"<div><p>Thermal hazards in deep mines can be mined synergistically with the deposit as associated geothermal energy resources. Backfill heat exchangers (BFHEs) as a combination of mine backfilling and ground heat exchanger technology are one of the effective methods to realize ore deposit-geothermal energy synergy mining. However, in the complex environment of deep mines, BFHEs will inevitably suffer from fracture damage during long-term heat storage/release cycle operation, which will affect their working performance. To address this problem, this paper established a scaled-down experimental setup for fractured BFHEs units, and used the experimental data to verify the accuracy of the established three-dimensional transient heat transfer mathematical model of the BFHEs unit. Numerical simulation methods were used to investigate the effects of the position, aperture and fractured depth of a single fracture on the heat extraction performance of the BFHEs unit under fully dry or fully saturated working conditions. Significant differences were found in the effect of different fracture positions on the heat extraction capacity of the BFHEs unit. The extraction of geothermal heat by the BFHEs unit was favored when it was in the middle of two tubes, while the opposite was true for other positions. The effect of fracture on the heat extraction capacity of the BFHEs unit increased linearly with fracture aperture. The effect of the fractured depth was relatively greater in the 1/2–3/4 <em>H</em><sub>b</sub> range. The presence of groundwater significantly reduced the effect of the fracture. The effect of the fracture on the heat extraction capacity of the BFHEs unit was reduced by more than 80 % by changing the operating conditions from fully dry to fully saturated condition. The overall effect of a fracture on the heat extraction capacity of the BFHEs unit was not significant, with a 5 mm wide fracture having an effect of no more than 2.5 %, even under the fully dry condition. However, there was a combined effect of multiple fractures, and for a deposit size of 900 × 7 × 80 m, ten 2 mm apertures fractures would results in a maximum reduction of geothermal extraction from BFHEs by 8527 GJ in 10 years, which was equivalent to the heat load of a 13,753 m<sup>2</sup> building for one winter in the cold climate of China.</p></div>","PeriodicalId":55095,"journal":{"name":"Geothermics","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141073313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
期刊
Geothermics
全部 Acc. Chem. Res. ACS Applied Bio Materials ACS Appl. Electron. Mater. ACS Appl. Energy Mater. ACS Appl. Mater. Interfaces ACS Appl. Nano Mater. ACS Appl. Polym. Mater. ACS BIOMATER-SCI ENG ACS Catal. ACS Cent. Sci. ACS Chem. Biol. ACS Chemical Health & Safety ACS Chem. Neurosci. ACS Comb. Sci. ACS Earth Space Chem. ACS Energy Lett. ACS Infect. Dis. ACS Macro Lett. ACS Mater. Lett. ACS Med. Chem. Lett. ACS Nano ACS Omega ACS Photonics ACS Sens. ACS Sustainable Chem. Eng. ACS Synth. Biol. Anal. Chem. BIOCHEMISTRY-US Bioconjugate Chem. BIOMACROMOLECULES Chem. Res. Toxicol. Chem. Rev. Chem. Mater. CRYST GROWTH DES ENERG FUEL Environ. Sci. Technol. Environ. Sci. Technol. Lett. Eur. J. Inorg. Chem. IND ENG CHEM RES Inorg. Chem. J. Agric. Food. Chem. J. Chem. Eng. Data J. Chem. Educ. J. Chem. Inf. Model. J. Chem. Theory Comput. J. Med. Chem. J. Nat. Prod. J PROTEOME RES J. Am. Chem. Soc. LANGMUIR MACROMOLECULES Mol. Pharmaceutics Nano Lett. Org. Lett. ORG PROCESS RES DEV ORGANOMETALLICS J. Org. Chem. J. Phys. Chem. J. Phys. Chem. A J. Phys. Chem. B J. Phys. Chem. C J. Phys. Chem. Lett. Analyst Anal. Methods Biomater. Sci. Catal. Sci. Technol. Chem. Commun. Chem. Soc. Rev. CHEM EDUC RES PRACT CRYSTENGCOMM Dalton Trans. Energy Environ. Sci. ENVIRON SCI-NANO ENVIRON SCI-PROC IMP ENVIRON SCI-WAT RES Faraday Discuss. Food Funct. Green Chem. Inorg. Chem. Front. Integr. Biol. J. Anal. At. Spectrom. J. Mater. Chem. A J. Mater. Chem. B J. Mater. Chem. C Lab Chip Mater. Chem. Front. Mater. Horiz. MEDCHEMCOMM Metallomics Mol. Biosyst. Mol. Syst. Des. Eng. Nanoscale Nanoscale Horiz. Nat. Prod. Rep. New J. Chem. Org. Biomol. Chem. Org. Chem. Front. PHOTOCH PHOTOBIO SCI PCCP Polym. Chem.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 联系我们:info@booksci.cn
Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。
Copyright © 2023 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1