The Influence Law of Oil Relative Permeability on Water Cut

Water cut is a key evaluation parameter for reservoir development evaluation. Relative permeability curve reflects reservoir characteristics and fluid characteristics. It is important to figure out the influence law of oil relative permeability on water cut. Based on the 269 relative permeability curves of Bohai oilfields, the distribution of oil index of Bohai oilfields were studied. On the basis, combined with Corey expression of relative permeability and fractional flow equation, the theoretical relationship between oil index and water cut increasing rate was established. Three end points of water cut increasing rate curve were proposed and the influence law between three end points and oil index was studied. The results show that the oil index has a linear relationship with three end points. When the value of water oil mobile ratio is large than 1, with the increase of oil index, maximum value of water cut increasing rate gradually increase. When the value of water oil mobile ratio is less than 10, oil index has great effect on recovery percent when water cut increasing rate reaches to the maximum value as well as water cut when water cut increasing rate reaches to the maximum value. The application of SS field shows that the theoretical value is consistent with the field data.

Research on mechanism of groundwater pollution from mine water in abandoned mines

In order to understand the mechanism and regularity of the groundwater contamination from mine water of abandoned mines, experiments were conducted on an abandoned coal mine in Fuxin, a representative city with lots of mine water in northeast China. The groundwater pollution from different contaminants of coal-mining voids （total hardness, SO4^2-, CI^- and total Fe） and pollution factors transportation situation in the coal rock were simulated by soil column experiment under the conditions of mine water leaching and main water leaching （similar to rainwater leaching）, and the water-rock interaction mechanism was discussed during mine water infiltration through saturated coal rock by application of principle of mass conservation, based on physical properties of coal rock, as well as monitored chemical composition. The results show that, compared with the clear water leaching process, trends of change in pollutant concentrations presented different characteristics in the mine water leaching process. Groundwater is contaminated by the water rock interactions such as migration ＆ accumulation, adsorption ＆ transformation, dissolution ＆ desorption and ion exchange during the mine water permeation. The experiments also suggest that at first dissolution rate of some kinds of dissoluble salts is high, but it decreases with leaching time, even to zero during both the mine water leaching and main water leaching.

Contents of soil organic carbon and nitrogen in water-stable aggregates in abandoned agricultural lands in an arid ecosystem of Northwest China

Soil organic matter content in water-stable aggregates（WSA） in the arid ecosystems（abandoned agricultural lands especially） of China is poorly understood. In this study, we examined the WSA sizes and stability, and soil organic carbon（OC） and nitrogen（N） contents in agricultural lands with abandonment ages of 0, 3, 12, 20, 30 and 40 years, respectively, in the Minqin Oasis of Northwest China. The total soil OC and N contents at depths of 0–20, 20–40 and 40–60 cm in abandoned agricultural lands were compared to those in cultivated land（the control）. Agricultural land abandonment significantly（P0.25 mm） as the age of agricultural land abandonment increased. The effect of abandonment ages of agricultural lands on MWD was determined by the changes of OC and N accumulation in WSA sizes ＆gt;2 mm. The total OC and N contents presented a stratification phenomenon across soil depths in this arid ecosystem. That is, both of them decreased significantly at depths of 0–20 and 40–60 cm while increased at the depth of 20–40 cm. The WSA sizes ＆lt;0.053 mm had the highest soil OC and N contents（accounting for 51.41%–55.59% and 42.61%–48.94% of their total, respectively）. Soil OC and N contents in microaggregates（sizes 0.053–0.25 mm） were the dominant factors that influenced the variations of total OC and N contents in abandoned agricultural lands. The results of this study suggested that agricultural land abandonment may result in the recovery of WSA stability and the shifting of soil organic matter from the silt＋clay（＆lt;0.053 mm） and microaggregate fractions to the macroaggregate fractions. However, agricultural land abandonment did not increase total soil OC and N contents in the short-term.

Oilfield geothermal resources of the Upper Assam Petroliferous Basin,NE India

Extracting geothermal energy from the oil-producing fields is an experimental venture globally.The exploitation and utilization of geothermal energy can partly reduce the larger dependence on conventional non-renewable energy sources like oil,gas,coal,and other fossil fuels,and has a bright prospect.The Upper Assam Basin is a mature petroliferous basin of NE India,where there are several hundred low production,high water cut,or abandoned oil and gas wells that can be retrofitted as geothermal wells instead of drilling new ones.This will help bridge the gap of growing energy demand and limited supply in energy-deficient state like Assam.Situated away from the active plate boundaries and in lack of active volcanism,the Upper Assam Basin remains a low-to-medium enthalpy geothermal fluid regime.The deeper reservoir in this regard can,therefore,be the best candidate for the introspection of the potential geothermal energy reservoir reconnaissance.The selection of a deeper horizon considered in the present case has been the stratified reservoirs of the Lakadong-Therria(Lk-Th)Formation,Sylhet Group of the Lower Eocene age occurring at a variable depth of 3400 me 4600 m.The Lk-Th Formation possesses a fair-quality reservoir with lateral continuity and favourable petrophysical properties.In this study,representative gamma-ray(GR)and resistivity(R)logs were examined to work out lithology,and bed boundary demarcation,etc.The total Formation thickness varies from 97 to 157 m;the individual sand body thickness is up to 6 m.Other reservoir parameters,e.g.,porosity(φ=8-33%),water saturation(S_(w)=4.57-95.15%),geothermal gradient(2.71℃/100m to 3.92 C/100 m at 4300 m and 3608 m)respectively,and theoretical estimate of high heat flux in the range 70e100 mW/m^(2)/s,are the necessary yard-stick to measure the subsurface geothermal reserves.Efficient energy extraction will have the potential in facilitating energy utilization for industrial purposes,especially in tea processing units present nearby oilfields and also for power generation by the binary mechanism.

Analytic Solution of Interaction Between Surface Waves and Floating Elastic Plates with Elastic End-Restraints

Based on the dynamic theories of water waves and Mindlin plates, the analytic solution of interaction between smface waves and two-dimensional floating elastic plates with edge-restraint is constructed by use of the Wiener-Hopf technique. Firstly, without regard for elastic edge restraint, the wave-induced responses of elastic floating plate analyzed by the present method are in good agreement with the results from literature and experimental results. Therefore, it can be shown that the present method is valid. Secondly, three end-restraint cases （i.e., the left-end elastic restraints, the both-end elastic restraints, and the right-end elastic restraints） are proposed to reduce the vibration of floating plates, in which the spring is used to connect the sea bottom and the floating plate＇ s left （ or right ） edge. The relations between the spring stiffness and the parameters of wave-induced responses of floating plates are discussed. Moreover, the effective method to reduce the vibration of floating elastic plates can be obtained through comparison.

考虑采动效应的闭坑矿井水硫酸盐污染规律

高硫煤矿闭坑后成为埋藏在地表以下深部的产酸污染场,对相邻含水层和周边环境造成了潜在危害,且因采动效应影响和矿井空间分布复杂导致相邻含水层的污染过程与污染程度评价困难。以某闭坑矿区为研究对象,选取SO_(4)^(2-)作为特征污染物,考虑多煤层采动裂隙对含水层结构的破坏影响,运用数值模拟技术对闭坑矿区酸性矿井水中SO_(4)^(2-)污染迁移特征进行研究,并分析流体扩散系数对含水层污染物运移的影响。结果表明:SO_(4)^(2-)在二叠系童子岩组砂岩含水层中水平迁移面积随时间增大而增大,增大速率逐渐减小,垂向渗透系数扩大10倍,空间变异性增强;闭坑5、10、15a后,最大水平迁移距离分别为215、414、612m,最大垂向迁移距离分别达到50、65、70m;而扩散系数越大,产酸时间越长,SO_(4)^(2-)迁移距离和污染范围将随之增大,相较于水平方向,垂向上SO_(4)^(2-)浓度变化对扩散系数的敏感度更高。基于模拟结果,结合闭坑矿区实际条件,针对性提出了“源头减量-过程阻断-末端治理”的综合防控与治理方案。研究结果将为该闭坑煤矿酸性矿井水污染治理与防控提供理论基础,也为其他同类矿井提供科学借鉴。

引江济淮工程(河南段)水资源调配系统设计与开发

为强化引江济淮工程(河南段)水资源统一调配,基于Spring Boot和Vue前后端分离开发的模式,利用天地图API、WebGL、Echarts等技术设计研发引江济淮工程(河南段)水资源调配系统。从设计思路、功能界面、关键技术3个角度论述系统设计思路和实现过程,从而实现地理信息服务、供需水预测、水资源优化配置、水资源优化调度等功能,实现水量分配可视化、运行调度智能化和跨流域调水管控一体化。系统测试结果表明:引江济淮工程(河南段)水资源调配系统的建立提高了受水区水资源精细化管理的水平,解决了引江济淮工程(河南段)跨流域调水的配置难题,为受水区水资源高效利用提供有效的技术支撑。

国外绿水经济发展经验研究

进入新发展阶段,人们对水资源的需求由过去单纯的物质和文化需求拓展为美好生活需要的多方面需求。最突出的变化是我国水经济形态发生了深刻变化,诞生一批水经济新业态,笔者认为凡是直接或者间接利用“绿水”来引导资源发挥作用,推动生产力发展的经济形态就是绿水经济。绿水经济在发达国家发展多年,形成了一批具有代表性的经济形态。梳理选取“绿水+高端农业”“绿水+新型工业”“绿水+旅游”“绿水+健康”四个代表性经济形态,剖析各典型经济形态的具体做法,总结提炼主要经验,并提出我国发展绿水经济的政策建议。

废弃矿区周边受污染水体生物修复技术

废弃矿区中受污染的水体可能会渗入地下水或河流,导致附近的水源污染。为此,采用生物修复技术,对废弃矿区周边受污染水体的修复方法展开研究。分析了矿区周边环境以及相关气候信息,确定该矿区周边污染水体污染物分布特征,根据分布结果布设样本测试点;利用生物膜法在样本测试点中进行污染水体的修复,修复过程中,需要对微生物实施培养、驯化,进一步增加微生物降解污水的活性;将驯化好的污泥转置进IC厌氧反应器中,产生氧化生物膜,投入测试点水域中,通过污泥吸附作用产生氧化生物膜,实现污染水体生物修复。实验结果表明,利用生物膜方法对污染水体进行修复,能够有效去除水体中总石油烃、多环芳烃等污染物质,并中和水体酸碱度,使水体完成修复后达到可排放安全标准。

基于氢氧同位素的平原湖荡地表水与地下水转化研究

地表水与地下水间的相互转化以及量化地下水补给量是湖泊水循环研究的重要内容。本文采集了元荡湖区域湖水、地下水样品,测试了其氢氧稳定同位素组成和水化学组成,运用Piper三线图分析其水化学类型、通过钻孔实测的地下水埋深绘制元荡湖区域旱季(2022年12月)和雨季(2023年6月)的地下水水位等值线图,结合电导率(EC)和溶解性总固体(TDS)定性分析地表水-地下水之间的转化关系,利用同位素水量平衡方程、线性端元混合模型定量评价了湖水、地下水、河水和降水之间的转化量。结果表明,研究区湖水和地下水的水化学类型均为HCO_(3)^(-)·SO_(4)^(2-)·Ca^(2+)·Na^(+)·Mg^(2+),旱季和雨季湖水均受到地下水的补给,拟合得到的湖水旱季、雨季氢氧稳定同位素线性回归方程表明雨季斜率较小,蒸发更为强烈。湖水主要由河水、地下水和降水补给,其三者在旱季的补给比例分别为59%、26%和15%,在雨季的补给比例分别为23%、39%和38%。本文成果为元荡湖区域以及太湖流域的综合治理提供了科学依据。

考虑发电与弃水风险的梯级水电站水库风险调度模型

为量化梯级水电站水库调度过程中的风险形势,提出了预报信息驱动的梯级水电站水库风险调度模型。基于长短期记忆(LSTM)神经网络建立风险形势预测模型,通过构造预报入库径流、水库运行工况、调度决策与出力破坏程度和弃水量之间的映射关系,动态推演复杂工况下梯级水电站水库调度风险;建立基于风险形势的梯级水电站水库调度模型,提出发电不足风险预控模式和弃水风险预控模式。选取雅砻江流域下游锦屏一级和二滩水库组成的梯级水电站水库作为实例研究,结果表明:与常规发电量最大模型相比,风险调度模型通过提前降低出力来补偿未来出力破坏时段的发电量,锦屏一级和二滩水电站分别减小出力破坏程度46%、63%,通过提前增加发电流量预留库容来缓解蓄水期后续时段的弃水量,锦屏一级和二滩水电站分别降低弃水流量4.8%、5.4%;风险形势预测模型能够将径流不确定性嵌入风险调度模型中,通过风险预控决策动态响应水电站水库调度运行状态和径流形势变化,在保证梯级发电量的同时有效降低调度风险。

露天矿地下水控制技术及对边坡稳定性的影响

我国富水露天矿多且涌水量大,若矿山地下水或边坡处治不当,将面临着“水患难止、边坡难固、有矿难采”的窘境。为解决露天矿遇到的水患和边坡失稳的问题,基于我国露天矿先后发展的垂直疏水孔、水平疏水孔、坑下大口径疏水孔和井群疏水等抽排方式,坑底泄水巷、基坑降水和辐射井疏干等疏放方式以及钻孔注浆帷幕、地下混凝土连续墙帷幕、钻孔咬合桩帷幕、防渗膜帷幕等截水帷幕和地层回灌水帷幕等多种地下水控制技术;开展了不同露天矿地下水控制技术对地下水位、端帮边坡岩土体力学性质变化、坡体应力变化和边坡稳定性系数影响的研究,分析了截水帷幕作用下地下水位抬升与边坡稳定性变化规律。研究结果表明:通过抽排方式、疏放方式将露天矿山地下水疏干或疏降可有效降低地下水位,减少边坡岩土体含水率,提高边坡岩土体黏聚力和内摩擦角,减小坡体的静水压力和水平推力,整体提高边坡稳定性系数,但大量疏排地下水又造成水资源的浪费和污染;截水帷幕能够解决疏排降水造成的地下水位下降幅度太大、疏排水量巨大、水资源浪费和污染的问题;在截水帷幕作用下,露天矿截水帷幕外侧水位不断抬升,引起截水帷幕外侧边坡岩土体含水率增加、黏聚力和内摩擦角减小、坡体的静水压力和水平推力增大,而截水帷幕内侧边坡岩土体含水率减小、黏聚力和内摩擦角增大、坡体的静水压力和水平推力减小,从而引起露天矿边坡稳定性系数略有降低;通过截水帷幕可以控制露天矿边坡地下水位,进而保持边坡岩土体力学参数在合理范围,维持边坡稳定性系数在安全区间,实现露天矿地下水资源保护与边坡安全的平衡。

水-瓦斯耦合作用下煤岩抗压特性劣化试验研究

闭坑高瓦斯矿井中煤岩体在水和瓦斯的劣化作用下力学特性劣化,这将直接影响其稳定性和安全性。为研究水-瓦斯耦合作用下煤岩抗压特性,基于水-岩-气耦合试验系统,开展了浸泡环境下的全水浸(EW)、半水浸半气浸(WG)及全气浸(EG)煤样和干燥(CZ)煤样的单轴压缩试验,分析了煤样抗压强度及变形破坏特征,并从煤样浸泡前后的组分、宏观结构及破裂断口细观特征的角度,揭示了水-瓦斯耦合作用下煤岩的宏观、细观劣化机制。结果表明,在三种浸泡条件下,煤样抗压强度较干燥煤样均降低,EG组、WG组和EW组煤样抗压强度分别降低了18.92%、38.31%和53.45%,三种浸泡条件下煤样破坏模式由干燥煤样的剪切破坏转变为剪切-拉伸混合式破坏,破坏程度也随之增大,煤样由脆性破坏转变为塑性破坏,导致浸泡后煤样局部化带范围和错动程度增大;煤样在三种浸泡环境中劣化效果主要表现为:1)水和瓦斯的侵入导致煤样内部黏土矿物分解和析出,与CZ组相比,EG组、WG组和EW组煤样平均黏土矿物含量分别降低了3.8%、28.85%和45.94%,煤样孔隙结构发生改变;2)各组煤样浸泡后表面出现劣化效应,EG组表面孔隙发育程度劣于EW组,且EW组煤样表面出现剥落现象,WG组煤样水浸部分孔隙发育程度要胜于气浸部分;3)水和瓦斯的劣化作用使煤样内部孔隙结构发生改变,EW组、WG组和EG组煤样破裂断口平均孔隙率较CZ组分别增加了706.84%、362.95%、147.47%。在三种浸泡环境下煤样初始承载结构被破坏,降低了煤样破坏前储存能量的能力,破坏后煤样内部的剩余弹性能降低,耗散能增加,声发射累计振铃计数降低。上述研究对于认识闭坑高瓦斯矿井中煤岩体的稳定性具有一定的参考意义。

不确定来水条件下龙羊峡水库年末水位优化

以黄河上游多年调节水库龙羊峡及下游刘家峡水库为研究对象,考虑来水不确定性影响,建立梯级水库群多目标随机优化模型,并基于理想点法(technique for order preference by similarity to an ideal solution,TOPSIS)决策方法,求解当年发电量与年末水位Pareto方案集中最佳方案,探讨来水频率及起调水位对年末水位和发电量的影响,验证年末期望水位保证多年调节水库发电效益的可靠性。结果表明:在不确定来水条件下,龙羊峡水库年末期望水位与龙羊峡水库、刘家峡水库年期望发电量之间存在竞争关系;龙羊峡水库来水频率越低、起调水位越高时,龙羊峡水库年末水位越高,龙羊峡水库、刘家峡水库发电量越大;基于提出的年末水位优化方法可大幅缩减龙羊峡水库现行调度方式下年末水位范围,且保障发电效益的可靠性在98%以上。

超长公路隧道施工对水土保持的影响及其对策研究

天山胜利隧道地处天山1号冰川、二级水源地保护区、多个国家森林公园等环境脆弱区域内,建设过程中的水土保持问题对当地生态环境保护具有重要意义,调研发现影响水土流失的主要因素为隧道弃渣场的防护、占用场地和影响区域表层土的利用、施工废水及隧道涌水、隧道建设附属设施防护和恢复等。通过室内试验与数值模拟相结合,确定了隧道弃渣场的选址位置、施工废水及隧道涌水处理方法、临时场地设施防护和修复方法。

珠江口潜水镭同位素时空特征及其对海底地下水排泄通量测算的影响研究

准确选取具有代表性的地下水端元是采用镭同位素示踪法量化海底地下水排泄(SGD)通量的关键。本研究分析了珠江三角洲潜水^(224)Ra与^(223)Ra的时空分布特征,评估了其对SGD通量计算的影响。结果表明,从潮间带近端至远端,潮间带潜水盐度和镭活度总体上表现为先下降后升高;相近盐度下,不同潮滩潮间带潜水镭活度无量级差别,仅随盐度上升的变化趋势略有差异;河口内外潮间带潜水的^(224)Ra活度最大相差(1986.8±94.5)dpm/100L,导致测算的SGD差异可达(25.2±9.6)×10^(8)m^(3)/d;以砂质潮滩为例,测算的旱、雨季SGD通量差异可达(2.3±1.6)×10^(8)m^(3)/d。SGD通量对潜水端元取值的敏感性分析显示,盐度影响最大,季节影响次之,潮滩性质影响最小。因此选择镭同位素趋近解吸平衡的高盐度潮间带潜水作为代表性潜水端元进行SGD通量测算较为合理。

大庆油田二类油层注聚时机研究

大庆油田聚驱开发对象已由一类油层向二类油层转变,以往基于一类油层区块建立的标准已不适用,需要开展适合于二类油层的注聚时机研究。基于二类油层地质特征和开发状况,利用数值模拟方法建立二类油层地质模型,研究开始注聚时含水率和结束注聚时含水率对聚驱开发效果的影响,并结合现场进行验证,确定合理的开始和结束注聚时机。研究结果表明,在结束注聚时含水率相同情况下,开始注聚时含水率越高,聚驱阶段采出程度越低,聚合物用量越大,吨聚增油量越低,含水下降幅度越小,含水最低值越高。即开始注聚时含水率越低,聚驱效果越好。在开始注聚时含水率相同情况下,结束注聚时含水率越高,聚合物用量、聚驱阶段采出程度越高,吨聚增油量越低。当水驱至含水率96%时开始注聚,选择含水回升到96%~97%时结束注聚比较合理,含水最好不要超过97%。

黑臭水体河底末端修复治理研究

分析黑臭水体的形成原因,从黑臭水体评价、水生动物修复、人工曝气、微生物强化修复几方面阐述黑臭水体河底末端修复治理技术,并结合相关案例,根据黑臭水体的修复治理需要,研究黑臭水体河底末端修复治理策略,解决水体污染问题,保证污染治理效果。

Evaluation method of underground water storage space and thermal reservoir model in abandoned mine

A large number of mines are closed or abandoned every year in China.Geothermal utilization is one of the important ways to efficiently reuse underground resources in abandoned mines.How to calculate the volume and distribution of underground water storage space is the key to accurately evaluate the sustainable geothermal production in abandoned mines.In this paper,according to the multi-scale characteristics of the underground space in abandoned mine,the flow and heat transfer equations in the multi-scale space are sorted out systematically,and the calculation methods of different secondary space volumes are derived in detail.Taking Jiahe abandoned mine as the background,the volume and distribution of underground secondary space are calculated,and three heat storage evaluation models considering different water storage spaces are established by using COMSOL.The simulation results show that there are great differences among different models,and the results of the equivalent porous media model considering the multi-scale space are most consistent with the reality.Sensitivity analyses of key parameters model results indicated that the heat production is closely related to not only the recharge flow rate but also the recharge temperature and operating time.Furthermore,the energy saving and emission reduction benefits of geothermal utilization in abandoned mines are calculated,the results show that geothermal utilization of abandoned mines can effectively reduce energy consumption and CO_(2)emissions,and it has great economic benefits.

山地城市雨源型河道水环境综合治理对策及措施探讨

重庆市溉澜溪属于长江一级支流,是典型的山地雨源型河道,以往多次整改效果却不明显。本工程以溉澜溪河道实现准Ⅳ类(除TN外,其他均达到Ⅳ类)水质为工程目标,本底调研掌握管涵的水质、水量,针对河道容量小、自净能力弱、源头雨污分流不彻底、地下水丰富且污染程度重、底泥淤积量大等问题,系统治理方案采用源头控源截污+末端处理治理技术,源头雨污分流改造降低污染负荷,末端再修建水质站处理剩余污水,并实现河道补水功能。在河道起点提标改造现状新华水质站工艺,出水满足河道日常生态补水需要,末端新建溉澜溪水质提升站处理剩余污水,具备雨后河道水质快速更新的功能,两座水质站出水水质满足准Ⅳ类标准,通过在线监测流量数据用以预测水质处理站规模在行业内具有创新意义。通过治理溉澜溪河道已彻底消除黑臭,重现清水绿岸、鱼翔浅底的美丽景象。