A STUDY ON TRANSIENT FLUID FLOW OF HORIZONTAL WELLS IN DUAL-PERMEABILITY MEDIA

To adopt horizontal wells in dual media reservoirs,a good understanding of the related fluid flows is necessary.Most of the recent studies focus on dual porosity media instead of dual permeability media.In this article,through both integral transformation and sink-source superposition,a new Laplace-domain solution is obtained for the slightly-compressible fluid flow in the 3-D dual-permeability media in which the horizontal well is operating in a constant rate of production.Major asymptotic characteristics of diagnosis curves of dimensionless downhole pressure are analyzed by the limited analysis.Effects of parameters of dual-permeability media including mobility ratio κ,storativity ratio ω and inter-porosity flow parameter κ on the downhole pressure are studied by using the Laplace numerical inversion.The new solution obtained in this article includes and improves the previous results and then can be used as a basis for either pressure transient analysis or formation behavior evaluation for the typical reservoir with horizontal wells.     

2010-2019年黄河干流兰州和白银段水质时空变化特征

基于综合污染指数法,结合单因子污染指数法及累积距平法等多种统计分析方法,定量分析了黄河流域兰州和白银段7个监测断面水质时空变化特征.结果 表明:兰州段和白银段2010-2019年水质综合状况良好,各监测断面综合污染指数均在0.25以下;监测断面水质空间差异显著(P＜0.05),兰州段整体水质优于白银段,扶和桥断面水质显...     

冰期河湖与大气的热交换模型

河湖与大气的热交换模型是计算分析冰凌形成、发展、消融时空变化规律的基础.基于现有太阳辐射、长波辐射、蒸发和对流模型研究成果,以现场冰情要素观测及历史天气资料为依据,建立了适用于冰期计算分析的河湖与大气的热交换非线性模型.提出了考虑晴天散射的太阳辐射计算模型,以Iziomon公式计算大气长波逆辐射,以俄罗斯冬季公式计算蒸...     

The influence of hydro‐climatic and anthropogenic effects on the long‐term variation of commercial fisheries in a large floodplain river

This study deals with the effects of climate fluctuations and anthropogenic impacts on fisheries of Paraná River over the last 100 years. It is the first attempt to appraise the influence of hydro‐climatic and anthropogenic variables on the population changes of the most important inland fisheries of Argentina. Datasets covering more than eight decades (1935–2016) of a number of frequent and abundant commercial species inhabiting the main channel as well as the large floodplain of Paraná River were used. Our results suggest that fish catches and structure changed over time. Long and short‐term changes and reductions were closely related to fluctuations of 18 hydro‐climatic variables. Positive effects on the ichthyofauna were recorded during humid periods (1930–1940 and 1970–2000), when the frequency of large spring–summer floods increased. An increase in anthropic impacts (accounted for with nine variables) were recorded during the last two decades. We highlight the usefulness of the approach to support the management of the resources, ensuring sustainability of commercial fish assemblages and the long‐term conservation of biodiversity in big rivers.     

万家寨引黄工程联接段输水建筑物原型水力量测

山西省万家寨引黄工程联接段输水建筑物原型水力量测是利用已安装在系统中的压力表、压力式水位计、超声波流量计、薄壁堰、水尺和外夹式超声波流量计等,通过对输水建筑物水流压力(水位)、流量和糙率进行监测和计算,较真实地反映输水建筑物的运行状态,为经济运行管理和安全供水提供有价值的借鉴资料.可供有关设计、运行和研究参考.     

松林河大金坪水电站引水隧洞断面优化设计

大金坪水电站为松林河干流河段规划建设的引水式电站,隧洞沿线地质条件复杂。隧洞施工初期,按照圆形断面顶拱进行了一期开挖,根据开挖揭示围岩地质条件及后期工程建设进度的要求,在隧洞布置、设计流量既定,保证电站机组出力不变,确保电站稳定安全运行的情况下进行合理的设计断面优化。对隧洞围岩条件良好洞段,论证取消隧洞原圆形钢筋混凝土衬砌,选定马蹄形锚喷断面作为最终优化断面形式。方法实用方便,满足精度要求。随着中小型水电站实际建设情况,此优化设计可作为隧洞施工中及时进行断面形式调整的一种简捷易行的思路。     

大渡河丹巴水电站上游调压室水力学研究

大渡河丹巴水电站调压室托马稳定断面面积大、涌波振幅大、波动衰减时间长、同一水力单元的相邻机组水力干扰情况严重。通过研究,明确了调压室小波动稳定性的控制标准、托马稳定断面的主要影响因素、研究了不同调压室布置方案在抑制涌波振幅、加速涌波衰减时间、相邻机组水力干扰程度等方面的差别,初步确定了调压室布置方案及机组运行方式。     

长大隧道涌水量影响因素评价分析的模糊层析分析法

采用模糊层析分析法(FAHP),建立长大隧道涌水量影响因素层析分析模型,并进行分析计算。依据模糊层析分析法,确定各因素的权重系数,并对其进行分析、排序。结果表明:地层岩性、断层破碎带长度是影响长大隧道涌水量的主要因素。该FAHP的应用为涌水量预测和相应防治措施的制定,提供了科学的理论依据。