水热型地热资源特征研究

从建阳漳墩地热勘查实际出发,研究水热型地热田地热资源特征。矿区通过区域地层、构造和岩浆岩体分布综合研究深部地热资源勘查,采用物化探手段和地热流体质量分析,圈定地热异常区,综合判断地热地质特征与深部断裂构造带关系,判断深部热源、热储及其盖层,构建地热水文模型,研究深井揭露深部热水。强调水文地质勘查,加强地热水文地质工作,提高分析寻找深部水热型地热资源研究程度,促进发展绿色能源。     

地热资源

地热资源是指能够为人类经济开发和利用的地热能、地热流体及其有用组分。地球内部热能资源包括地热流体及其有用组分。广义的地热资源包括:①地热过程的全部产物主要指天然蒸汽、热水和热卤水等。②由人工引入地热储的水、气或其他流体所产生的二次蒸汽和其他气体、热水、热卤水等。③由上述产物带出的副产品指价值比较高的矿物质。目前可探明的地热资源有5类:以蒸汽为主的地热资源;以液态水为主的地热资源;地压型地热资源;干热岩体型地热资源和     

冀中台陷(河北区域)地热资源特征研究

基于10年来的测温数据和地热井水质、水位的动态监测数据,分析了冀中台陷(河北区域)现今地温梯度、地温梯度平面分布特征以及4000m以浅不同热储层的地热资源类型与赋存规律,统计了冀中台陷现有地热井现状与水位变化情况,计算了冀中台陷四级构造单元的地热流体热量潜力模数,绘制了各热储层地热流体热量潜力分区图。建议雄安新区应积极利用蓟县-长城系热储,控制利用馆陶组热储,严禁开采明化镇热储。     

安徽皖南地区构造盆地及深大断裂地热潜力研究

皖南地区地热资源较为丰富,地下热水露头9处,其中7处沿着研究区北东向深大断裂及其次生断裂带出露,2处在具有断裂发育的构造盆地出露,说明区域地热与深大断裂和构造盆地关系密切。根据已有资料统计和已出露地热的特征,将皖南地区的地下热水赋存模型概括为断裂带状热储和构造盆地带状兼层状热储两种概念模型。皖南地区主要为中低温地热,研究区已出露地热多位于地温梯度较高处,一般位于莫霍面和居里面深度较浅的部位。对区域内15个调查点进行大地热流值计算,一般为40~80m W/m2。通过对深大断裂和构造盆地的地球物理解译分析,划分了断裂带状地热潜力区和构造盆地带状兼层状地热潜力区。具有地热潜力的深大断裂主要有高坦断裂、汤口断裂、岭-盘断裂、旌德断裂、绩溪断裂;具有地热潜力的构造盆地为宣广盆地、沿江盆地和绩溪盆地。     

鲁北地区地热资源区划研究

本文分析了新近系馆陶组热储．古近系东营组热储和下古生界寒武～奥陶系基岩热储三个热储层组,认为这些层组属具有勘探和开发意义的热储目的层组,特别是新近系馆陶系热储组具有良好的热储地质条件。并根据地质构造条件、热储类型、地温梯度特征对鲁北地热资源区进行划分。在地热资源区划的基础上,按优先开发、次优先开发、一般开发、远景开发的原则进行地热资源亚区划分,将鲁北地热资源划分为6个区划区和16个区划亚区。     

U型井取热不取水地热开采潜力及影响因素分析

取热不取水井筒闭循环采热工艺是开采地热水低产区、地热尾水回灌难地区地热资源的有效方式。为了研究U型井式闭循环地热系统对中低温砂岩地热资源的可持续开采能力,文章以河北任县已有的地热地质数据和短期供暖数据为基础,使用井-储耦合模拟程序T2WELL对U型井采热能力进行数值分析,探究U型井式闭循环地热系统对该研究区地热供暖的可持续潜力。此外,定量分析了不同关键工程参数对U型井提热能力的影响,以指导设计合理的U型井取热不取水地热开采方案。结果表明：U型井地热开采系统的产流温度和提热功率在同一个供暖季内随时间降低,在连续多个供暖季内也随时间降低,其变化趋势为先快后慢。基于文章模型研究,确定U型井式闭循环地热系统最适合的注采流量、回灌温度、水平井长度分别为60 m3/h,10℃和400 m。     

福建地热资源勘查研究

福建省位于中国东南沿海,靠近环太平洋地热带,有215处温泉分布,温泉分布密度居全国第3位。从上世纪70年代起,福建省就注重地热资源勘查和开发利用,漳州地热井在百米深度获得121.5℃,是中国东部地热的最高温度。福州最早建立地热水厂供水,也较早实现地热资源管理。福建地处中国南方首创了地热制冷,而且温泉养鳗等居全国领先。福建省地热属于裂隙型热储,地热地质条件复杂,但近些年来的地热勘查获得了更高温度和出水量,并在中国增强地热系统研究中考虑为备选靶区之一。搞好全省地热资源发展专项规划,按短期、中期、长期规划好全省的地热资源勘查和开发利用,十分必要。     

北京的地热资源及其开发利用前景

一前言地热资源是指在当前技术经济和地质环境条件下,人类能够科学、合理地开发出来的埋藏于地表以下岩石或流体中的热能及其伴生的有用组分。地热能与太阳能、风能、生物能、海洋能等统称为可再生能源。地热能只有转化为水、汽、干热气体或岩浆等形式才能为人类利用,通常把地热流体相对富集、具有一定渗透性并含载热流体的岩层或岩体破碎带称为热储,热储是地质勘探寻找和开发地热资源的重要目标。地热资源按其在地下的赋存状态可     

山西平遥汾河地堑地下热水勘探开发探讨

根据在山西平遥地下热水勘探凿井中取得的第一手资料，对汾河地堑地热资源勘探开发中的井位布置，所处地质构造、热储岩体、热储类型及热水富集特征等相关地热地质条件作粗浅探讨。     

太原盆地地下热水分布特征

依据山西中部断陷盆地的形成与发展,分析了太原盆地基底的地质构造特征,预测太原盆地平原区地下深部隐藏着丰富的地下热水,确认两个岩溶裂隙水系统,论述盆地热热源、地下热水形成的地热地质条件、热储分布、以及热水的化学特征,并提出地下热水的开发利用意见。     

水热型地热资源地球化学勘探技术研究进展

地球化学勘探技术在水热型地热资源勘探中的应用研究具有较长的历史,迄今已形成了一套基于气体与元素指标的勘探技术体系,涵盖了众多技术指标,且已在世界各地诸多地热田勘探研究中获得了广泛应用。结果揭示,在预测地热田发育有利部位、估算深部热储温度以及推断地热水来源等方面,地球化学勘探技术都可发挥其特有的作用,是一种经济有效的地热勘探技术,具有良好的应用前景。但地热地球化学勘探技术也面临其自身的局限性,其应用研究不仅受地热田类型的限制,而且目前主要集中于已知地热田上方的验证性研究,技术本身的多解性也较强。因此,在地热地球化学勘探技术完善与应用研究方面,还有待进一步深化。     

地热发电的投资经济分析

地热能是一种清洁的可再生能源,越来越多的国家宣布支持地热开发。地热发电必须考虑到影响成本的各种因素,地热发电的成本主要由初始投资和电力生产运行及维护成本两部分组成。地热项目具体的投资成本与资源特征和现场条件有着非常密切的关系,资源的温度、深度、化学特性和渗透性是影响发电成本的主要因素。与传统化石燃料发电相比,地热发电已具有相当的竞争力,在生命周期内地热发电厂的平均成本大大低于传统燃料发电厂。另外,地热发电还有抵消化石燃料价格波动对电力市场影响的作用,有利于促进农村和偏远地区经济发展,有利于能源供应多元化。当然,地热能发展也面临着一些障碍,包括钻井的成功率、地热技术尚不够完善以及项目启动成本高等。建议今后地热资源的利用不再仅局限于极少数高温地热项目中,而是尽可能发掘地热资源的所有潜力。     

地热资源的开发利用及可持续发展

地热资源作为一种新型能源矿产,具有分布广泛、易于开发等特点,其利用方式主要有地热发电和地热直接利用两种.我国具有良好的地热资源条件,主要为中低温地热资源.据计算,我国12个主要沉积盆地的地热可开采资源量为7500×1018J,相当于2560×108t标煤.当前,我国地热资源利用方式主要以供暖、洗浴、种植等直接利用为主;地热发电发展缓慢,主要分布在西藏;利用热泵技术开发地热资源得到了快速发展;油区地热资源的开发利用也取得了良好的经济和社会效益.但同时我国地热资源产业也面临着一些问题,包括大部分地区尚未开展地热资源勘查评价,影响了地热资源规划的制订及地热产业的发展;防腐、防垢技术还需要进一步加强研究;地热回灌率普遍过低;增强型地热系统研究有待加强等.为了促进地热资源的可持续发展,建议在加大地热资源勘查力度的同时,应以浅层地温能和热水型地热资源为主,发挥热泵技术的优势,开展地热资源的综合利用及梯级利用;重视和加快油气区地热资源的利用;在西藏等适宜地区加大高温地热能发电利用;集中全国优势技术力量,在一两个有利区域开展增强型地热系统技术探索;此外,走回灌开发道路是地热资源开发利用的必然选择.     

北京平原地热资源与地热供暖

本文对北京平原地区地热资源条件和供暖现状进行了概述,分析了地热供暖技术的特点、优势以及当前制约其推广发展的“瓶颈”,针对北京平原地热资源的可持续发展提出了两点具体建议。     

Geothermal slim holes for small off-grid power projects

Economically viable, small (100 kW_e to 1000 kW_e), geothermal power generation units using slim holes are available for the production of electrical power in remote areas and for rural electrification in developing countries. Based on borehole data from geothermal fields in the United States and Japan, slim holes have been proven as adequate fuel sources for small-scale geothermal power plants (SSGPPs) and can deliver enough geothermal fluid to the wellhead in a baseload mode to be of practical interest for off-grid electrification projects. The electrical generating capacity of geothermal fluids which can be produced from typical slim holes (150-mm diameter or less), both by conventional, self-discharge, flash-steam methods for hotter geothermal reservoirs, and by binary-cycle technology with downhole pumps for low- to moderate-temperature reservoirs are estimated using a simplified theoretical approach. Depending mainly on reservoir temperature, the numerical simulations indicate that electrical capacities from a few hundred kilowatts to over one megawatt per slim hole are possible. In addition to the advantage of price per kilowatt-hour in off-grid applications, SSGPPs fueled by slim holes are far more environmentally benign than fossil-burning power plants, which is crucial in view of current worldwide climate-change concerns and burgeoning electricity demand in the less-developed and developing countries.     

Geochemistry and groundwater contamination in the La Selva geothermal system (Girona, Northeast Spain)

Hot spring waters of the La Selva geothermal system show high concentrations of Cl, F, Ca, Na, K, Li, Si, As, Ba, and Rb, whereas cold waters show low salinity, high concentrations of NO₃, and significant As content when mixed with geothermal waters.Modeling of the geothermal fluids indicates that the fluid is supersaturated with aragonite and calcite, which matches the travertine precipitation close to the present discharge areas. Moreover, the barite and fluorite are also are near equilibrium levels, indicating possible control of Ba and F solubility by these mineral phases, which also precipitate in some discharge areas. Likewise, the fluid is supersaturated with respect to quartz, indicating the possibility of siliceous precipitation near the discharge areas of the present geothermal fluids.Taking into account the Na-K, Na-K-Ca, and SiO₂-temperature geothermometers, the temperature of the reservoir may be estimated to be about 135 °C.The chemistry of the geothermal fluids has changed from a recent high-enthalpy system, which precipitated siliceous deposits, to the present low-enthalpy system, which precipitates carbonated deposits (travertine).Multivariate analysis of the groundwater shows high correlations between K, Ca, As, Br, Ag, and Ba, suggesting that As is introduced to the environment via geothermal fluids. Moreover, As concentrations in hot groundwater are associated with high concentrations of Li and Si, as has been observed in other geothermal fields. Metal concentrations in the hydrothermal deposits show high values of Ag, As, Ba, Pb, Sb, and Zn, mainly in the siliceous deposits of the town of Caldes de Malavella, where the geothermal system deposited materials with high As concentrations (123-441 ppm).The similarities between the geochemical characteristics of the hydrothermal deposits and the groundwater suggest that the metals in these deposits and fluids have the same origin.     

Classification of geothermal resources by exergy

Geothermal resources have been classified as low, medium and high enthalpy resources according to their reservoir fluid temperatures. There is no general agreement on the arbitrary temperature ranges used. Classification of a geothermal resource by its reservoir fluid temperature can be ambiguous because two independent properties are required to define the thermodynamic state of a fluid. Geothermal resources should be classified to reflect their ability to do thermodynamic work. In this paper, it is proposed that geothermal resources be classified as low, medium and high quality resources with reference to their specific exergy indices (SExI), SExI<0.05, 0.05SExI<0.5 and SExI0.5, respectively. The demarcation limits for these indices are exergies of saturated water and dry saturated steam at 1 bar absolute. These demarcation lines can be plotted on a Mollier diagram to form a classification map of geothermal resources.     

油区地热能开发新工艺的研究

在油区地热资源开发过程中,应用井内换热和尾水回灌的对井供热系统可以提高地热资源开发效益、避免地热水资源浪费和实现可持续发展。文章使用了地热储二维分布模型和井筒传热模型．通过对地热储的数值模拟预测了尾水回灌过程中地热储的压力响应和冷却效应,通过对井筒的热力计算得到了井内换热器的最优设计方法。计算结果表明,地热储对尾水回灌的压力响应非常迅速,压力场能很快达到稳定;回灌冷水的影响区集中在回灌井的周围,冷区半径增长的速度越来越慢。井内换热器在最佳设置深度时,经济效益达到最大值;井内换热器设置深度不变,增大载热水的流量经济效益将增加,但是获得的热能温度下降。     

Thermoluminescence as a new research tool for the evaluation of geothermal activity of the Kakkonda geothermal system, northeast Japan

The thermoluminescence glow-curve of quartz in volcanic and pyroclastic rocks of the Miocene and Quaternary in the Kakkonda geothermal field was divided into L (low), M (medium) and H (high) peaks in order of increasing temperature. Thermoluminescence emission is independent of stratigraphic boundaries but it is closely related to surface geothermal manifestations. Thermally stimulated processes of thermoluminescence caused by natural annealing occurred in the Quaternary after the eruption of the Tamagawa Welded Tuffs; radiation storage processes then began, as a consequence of the temperature drop. Thermoluminescence behavior indicates natural temperature manifestations, together with the paleo-temperature history.The H peak was thermally stable compared to the L and M peaks, and the area within which the relative intensity of the H peak is less than 5% coincides with the surface zone where dominant fluid flow is convective. In addition, L and M peaks indicate that a relatively low-temperature fluid mixes with the hot upflow around the western margin of the ascending flow zone.Thermoluminescence characteristics reflect paleo-temperature history and are related to geothermal fluid flow. Thermoluminescence is an effective exploration technique for evaluating natural temperature manifestations and subterranean heat flow in geothermal systems.     

Life cycle assessment of geothermal binary power plants using enhanced low-temperature reservoirs

Geothermal binary power plants that use low-temperature heat sources have gained increasing interest in the recent years due to political efforts to reduce greenhouse gas emissions and the consumption of finite energy resources. The construction of such plants requires large amounts of energy and material. Hence, the question arises if geothermal binary power plants are also environmentally promising from a cradle-to-grave point of view. In this context, a comprehensive Life Cycle Analysis (LCA) on geothermal power production from EGS (enhanced geothermal systems) low-temperature reservoirs is performed. The results of the analysis show that the environmental impacts are very much influenced by the geological conditions that can be obtained at a specific site. At sites with (above-) average geological conditions, geothermal binary power generation can significantly contribute to more sustainable power supply. At sites with less favorable conditions, only certain plant designs can make up for the energy and material input to lock up the geothermal reservoir by the provided energy. The main aspects of environmentally sound plants are enhancement of the reservoir productivity, reliable design of the deep wells and an efficient utilization of the geothermal fluid for net power and district heat production.