盐穴天然气地下储气库腔群优化配产模型

根据盐穴储气库注采运行特性,将储气库多腔注采运行考虑为一个系统,在满足城市调峰需求、溶腔注采井筒不被天然气冲蚀和溶腔最低运行压力3种约束限定条件下,以腔群总压降最小为优化目标,提出了盐穴储气库腔群配产模型,基于有约束条件的复形调优法对模型进行了求解,确定出库内各单腔的最佳采出量.模拟结果表明优化配产后各溶腔压降明显低于均产,优化配产后溶腔总压降低于等量配产0.717 MPa.对于大容积采气能力高的溶腔,可实现大流量的采气,研究成果可应用于盐穴储气库注采运行方案的确定及多腔优化生产调度.     

Dynamic simulation research on injection and withdrawal performance of underground salt cavern natural gas storage

Owing to perfect impermeability,dynamics stability,flexible and efficient operation mode and strong adjustment,underground salt cavern natural gas storage is especially adapted to be used for short-term dispatch.Based on characteristics of gas flow and heat transfer,dynamic mathematic models were built to simulate the injection and withdrawal performance of underground salt cavern gas storage.Temperature and pressure variations of natural gas in gas storage were simulated on the basis of building models during withdrawal operation,and factors affecting on the operation of gas storage were also analyzed.Therefore,these models can provide theore-tic foundation and technology support for the design,building and operation of salt cavern gas storage.     

内压对含软弱夹层盐岩储库稳定性影响的研究

通过建立含不同夹层厚度的圆柱形储库单腔三维模型,考虑不同恒压作用下长期蠕变,从腔体收缩率,围岩塑性区及位移矢量分布角度,分析运行内压对含软泥夹层盐岩腔体稳定性的影响。结果表明,腔体维持较高的运行压力,能有效减少腔体收缩,腔周塑性区及位移矢量发展,有利于腔体稳定。另外软泥夹层厚度在一定范围内增长对腔体的稳定性影响不太,在高内压作用下甚至可以忽略,这一结果对含软弱夹层层状盐岩腔体模型简化具有一定的指导意义。     

江汉盐穴储气库密封测试方法研究

盐穴井筒及腔体的密封性决定了盐穴能否储存天然气,还关系到储气库能否安全运行。通过对国外盐穴储气库密封性检测及评价技术的调研,以及对盐穴储气库密封性影响主要因素的分析,提出了适合江汉盐穴储气库的气体泄漏测试方法及评价标准。     

双井水平盐腔恒定内压的天然气储库

盐岩是国际公认的能源储存理想介质。中国盐岩呈层状分布并具有单层厚度薄、杂质含量高、含有众多不可溶夹层的特点,故地下能源储库更宜采用水平腔体形式。为保证水平盐腔的运营安全且实现整个候选场址能源储库总容积的最大化,提出双井水平盐腔恒定内压的储气库形式,即在水平腔体中对称均匀设置两口井,分别用于注采天然气和卤水,并保持运营过程中腔体内气压为恒定最大值。根据金坛盐岩实际地质构造及岩石力学参数,使用FLAC^3D有限差分软件,建立双井水平盐腔恒定内压储气库模型进行数值模拟,从稳定性、密闭性、可使用性和井喷分析4个方面研究其长期运营的可行性和安全性;另设置对照组模拟传统腔体的工作状态,与其进行对比。结果表明：双井水平盐腔恒定内压储气库满足长期运营安全性等各方面的要求,且其性能明显优于传统储气库;此外,该储气库形式还具有经济、灵活、调峰能力强,能很好地应对井喷,相同容积造价低,能充分利用盐层密集建腔等诸多优点,是适合中国盐岩特点的储气库形式。     

大型地下水封石油洞库围岩完整性、变形和稳定性分析

围岩完整性、变形和稳定性对地下水封石油洞库建造具有至关重要的影响。以我国首个在建的大型不衬砌地下水封石油储备库项目为背景,运用弹塑性理论,在室内岩石三轴试验基础上,研究了花岗岩地层大型不衬砌地下水封石油洞库围岩的完整性以及变形和稳定性。研究表明:岩石的完整性从剪胀出现开始受到破坏,采用剪胀起始点对应摩擦角可对地下工程围岩开挖松动区进行估算;该大型地下水封石油洞库洞室开挖松动区范围从0~15.6m不等,且与埋深成正比;由于开挖过程中应力路径与剪胀线关系不同,各洞室间中墙完整性变化趋势存在差异;洞壁围岩位移方向与山丘地表走势相关,拱顶沉降和水平收敛值在8~45mm之间;在洞室底板位置出现了拉应力区,在洞库两侧边墙下端和起拱处出现高剪应力区,在开挖过程中可能出现局部破坏现象。     

压力失控条件下盐岩储气库腔内压降规律解析

盐岩储气库在极端条件下压力失控工况的分析对储库运营安全控制有重要意义。基于理想气体1维定常流动理论,引入时间变量分别建立了井管管壁无摩擦和有摩擦两种情形下储库溶腔内部压力随时间变化的数学模型,用分离变量法求出井喷失控状态下储库腔内压力变化的解析表达式,并通过实验进行了对比验证。分析表明,盐岩储库腔压降时程曲线呈指数型衰...     

基于离散裂隙网络法的地下石油洞库洞室间水封性评价

为研究地下水封石油洞库洞室间水封性,依托黄岛地下水封石油洞库工程,采用离散裂隙网络法进行了7个不同工况的分析,分别获得了在不同水幕压力、洞室间液面差、洞室间距和裂隙倾角条件下的地下水头分布和流体渗流情况。研究结果表明:水幕压力增大、洞室间液面差减小与洞室间距增大均会改善洞库水封性;裂隙网络中裂隙倾角的变化会影响围岩的渗透张量,从而改变裂隙网络中地下水的渗流路径,继而影响地下水封石油洞库洞室间水封性;仅靠增加水幕系统压力并不能保证洞室间水封性,地下水封石油洞库相邻洞室水封设计应综合考虑储油情况、洞室间距、裂隙倾角等因素。     

支撑熔盐膜法脱除航天舱中 CO_2 的实验研究

对支撑熔盐膜法脱除航天舱中ＣＯ２进行了详细的研究,实验考察了熔盐膜端电压与操作电流间的关系,探讨了电流密度、阴极室ＣＯ２浓度、气体流量等因素对ＣＯ２传质通量及脱除率的影响。     

Current research into the use of supercritical CO_2 technology in shale gas exploitation

The use of supercritical CO_2 for shale gas extraction is a promising new technology. This paper explores current research into this process, looking at analysis of the mechanism of CH_4 displacement in nanoporous shale, the positive and negative effects accompanying its use for sequestration as well as organic extraction, the migration of elements and the swelling process, and the macro and micro control mechanisms involved in permeability enhancement in reservoirs. Fruitful directions for future research are also considered through comparison with hydraulic fracturing. The research findings indicate that Sc CO_2 fluid replacement can be used to increase gas production and seal up greenhouse gases as an effective, clean and safe method of shale gas exploitation. It is particularly effective for promoting the desorption of CH_4 in shale reservoirs that have developed fine neck-wide body pores, and the subtle structural changes effected by Sc CO_2 fluid in sensitive minerals in reservoirs with a high brittle mineral content also have a positive effect on permeability and storage capacity. The adsorption process has been characterized as consisting of three stages: short-term shrinkage, slow swelling, and stability; an expansion equation has been proposed for CO_2/CH_4 that incorporates competitive adsorption, collision desorption, and impingement re-adsorption. Sc CO_2 fracturing has been found to be more effective than hydraulic fracturing for dense reservoirs and more effective at linking up pore-micro-fissure-fracture systems.     

冲击荷载作用下地下岩洞的动应力分析

本文用动态光弹性方法,分析冲击荷载作用下岩洞周边的动应力分布和动应力集中系数。试验中针对规则、非现则两种直墙拱顶孔洞进行研究。采用落锤加载,微闪系统记录试验资料。文中给出冲击荷载作用后几个特定时刻岩洞周边的应力分布。试验结果表明:岩洞的动应力集中系数与孔型有关。被岩洞引起的应力扰动区域,由孔中心向四方扩展到离孔中心约相当于最大特征尺寸1.5倍的地方。     

A numerical modelling approach to assess the behaviour of underground cavern subjected to blast loads

The paper gives an insight into the behaviour of large underground caverns which are subjected to blast loads. Caverns are generally constructed in hard rock formation which compels us to use blasting methods for the excavation works. Comparative study was done between models with intact rock mass and discontinuities to assess the stability of cavern as a result of blast loads. Numerical modelling was performed with 3 dimensional distinct element code(3 DEC) to analyse the performance of cavern walls in terms of displacement and to compute peak particle velocities(PPV) both around the cavern periphery and at surface of models. Results showed that the velocity wave with higher frequency exhibited large displacements around the periphery of cavern. Computation of PPV showed that model with horizontal joint sets showed lower PPV in comparison to model with intact rock mass. PPV values were also analysed on the surface for model consisting vertical joints spaced at 4 m intervals. Comparative study of PPV on surface vertically above the blast location between models with horizontal joints spaced at 4 m and vertical joints at 4 m intervals were conducted. Results depicted higher magnitudes of PPV for model with vertical joints in comparison to model with horizontal joints.     

数控气压式柔性加载模型试验系统的研制及应用

地质力学模型试验中针对地应力的模拟,往往采用液压千斤顶刚性加载的方式,该加载方式具有以下不足:1)使得模型边界的位移同步一致,而模型应力则呈现非线性分布状态,与实际工程的地应力状态不符。2)无法应用于不同形状的洞室内,无法对含内压地下洞室(如隧洞内水压力、石油储备库油压等)进行有效模拟,因此成为制约有压洞室模拟的一个关键性难题。因此,有必要研制准确模拟洞腔内外压力的柔性加载装置。作者根据气压加载灵活的特性,设计研制了一套数控气压式柔性加载模型试验系统,有效实现了模型试验洞腔内的气压式柔性加载以及加载过程的自动化、数字化和可视化。通过气压式柔性加载控制系统能更真实地揭示深部软岩地下洞室围岩的非线性变形特征和破坏机理。将该系统应用于注采气压变化条件下盐岩储气库地质力学模型试验中,有效模拟了注采气压变化对盐岩地下洞腔的稳定性影响,获得了在不同注采气速率及不同气压条件下洞室收敛变形规律。试验表明,该实验系统可应用于有压洞室模型试验内压的有效模拟,具有广阔应用前景。     

电转气地质储能技术的经济性分析

电转气(power-to-gas)是一项将电能转化为高能量密度可燃气体的化学储能技术,该技术与地质储能相结合,有望满足未来大容量储能需求,并成为未来有效储能技术选择之一.电转气地质储能技术中涉及电离制氢、甲烷化、二氧化碳(CO2)地质储存、人工合成甲烷(CH4)地质储存4个阶段.由于电转气地质储能技术发展处于初步阶段,...     

层状盐岩小井间距双井水溶造腔流场相似模拟研究

为解决层状盐岩单井水溶造腔过程中建槽周期长,提管工艺复杂等问题,开展层状盐岩小井间距双井水溶造腔技术研究。拟采用选定物理法建立相似试验平台,探讨小井间距双井水溶造腔流场及浓度场特征,揭示双井水溶溶腔腔体扩展与流场的联系。结果表明：双井水溶造腔过程中腔体流场可以划分为4个区域：边界溶蚀区、浮羽流区、对流扩散区和底部饱和区,各个区域相互影响。浮羽流区是驱动流体运移的关键区域,根据浮羽流区流场特征建立相应的流场模型;根据宏观流动特征,对流扩散区分为强扩散区和弱扩散区;边界溶蚀区对双井水溶溶腔腔体扩展有显著影响;饱和区示踪特征不明显但浓度分层明显。通过对比分析双井造腔和单井造腔模型试验结果,发现双井水溶造腔工艺有利于盐穴建槽期,研究为小井间距双井水溶造腔技术的应用提供一定的理论基础,对盐穴储气库的优化建造具有重要意义。     

龙滩巨型地下洞室群锚固效应分析

广西龙滩水电站地下厂房是典型的大跨度、高边墙地下洞室群 ,其所在位置工程地质条件复杂 ,围岩为陡倾角层状结构岩体 ,且层间错动较发育 ,断层较多 .主厂房和调压井的高边墙以及洞室间岩柱的稳定性分析 ,是围岩锚喷支护设计的关键 .本文采用快速拉格朗日分析法 (FLAC)对洞室的开挖进行了模拟 ,分析了毛洞开挖和加锚开挖两种工况 ,得出了一些有益的结论 .     

盐穴储气库双井造腔技术现状及难点分析

目前我国在盐层建库主要采用单井溶腔技术,但常用的单井溶腔技术无论在造腔体积、建库周期等方面均已不能满足我国盐穴储气库建设日益增加的需求,而盐穴储气库双井溶腔技术具有增大注水排量、降低能耗、增大腔体体积、缩短建库周期等优点,因此在综合分析国外盐穴储气库双井溶腔技术及难点的基础上,指出腔体形态设计与控制、腔体形态监测与工艺参数优化等是国内盐穴储气库双井溶腔技术存在的主要问题,并提出了相应的解决措施。     

云南省碳中和技术路线与行动方案

为解决碳达峰碳中和技术路线和行动方案不明确、不清晰的问题,以云南省为研究对象,分析梳理了云南省的能源结构、碳排放现状、碳排放重点行业、林业碳汇情况等,归纳总结出云南省碳中和目标导向下的技术路线和行动方案.研究结果表明:云南省可再生资源丰富,应充分发挥绿色能源优势,大力发展水能、风能及太阳能等可再生能源.充分利用废弃矿山...     

Natural convection heat transfer of molten salt in a single energy storage tank

Heat transfer in molten salt in a cylinder tank is studied via simulation and experiment to obtain its natural convection heat transfer in a single energy storage tank. Simulation and experimental results show that the natural convection heat transfer of water in a cylinder tank fits well with Garon's correlation. However, significant deviations occur when Garon's correlation is used to predict the natural convection heat transfer of molten salt because of its high viscosity and low thermal conductivity. However, the simulated data of the natural convection heat transfer of molten salt fit well with those of the experimental results. Thus, a correlation that considers the effect of variable physical properties is proposed in this study to predict the natural convection heat transfer of molten salt. The deviation of the present data from the proposed correlation is less than ±20%. The results of this study can serve as a basis for the design of single energy storage tanks.     

CO_2 sequestration characteristics in the cementitious material based on gangue backfilling mining method

The increasing anthropogenic CO_2 emission and global warming has challenged the China and other countries to seek new and better ways to meet the world's increasing need for energy while reducing greenhouse gas emissions. The overall proposition of this research is to develop a brand-new CO_2 physical and chemical sequestration method by using solid waste of coal mining and cementitious material which are widely used for goaf backfilling in coal mining. This research developed a new testing system(constant temperature pressurized reaction chamber(CTPRC)) to study the effects of different initial parameters on mineral carbonation such as different initial water-binder ratio, initial sample porosity and initial carbon dioxide pressure. The experimental results show that the CO_2 consumption ratio is 15%,10% and 7% higher with relatively high initial water-binder ratio, initial sample porosity and initial CO_2 pressure within 48 h. In addition, some physical and chemical evidence was found through the electron microscope scanning and XRD test to further explain the above test results. This proposed research will provide critical parameters for optimizing CO_2 sequestration capacity in this cementitious backfilling material with forming agent.