A predictive model for well loss using fuzzy logic approach     

Abdüsselam Altunkaynak 《水文研究》2010,24(17):2400-2404

Simple methods for calculating well losses are important for well design and optimization of groundwater source operation. Well losses arise from both laminar flow within the aquifer and turbulent flow within the well, and are often ignored in theoretical aquifer test analysis. The Jacob ( 1947 ) and Rorabaugh ( 1953 ) techniques for predicting well losses are widely used in the literature; however, inherent in these techniques are the assumptions of linearity, normality and homoscedascity. In the Rorabaugh technique, prior knowledge, or prediction of, the parameters A, C and n is required for calculation of well losses. Unfortunately, as of yet, no method for adequately obtaining these parameters without experimental data and linear regression exist. For these reasons, the Rorabaugh methodology has some practical and realistic limitations. In this paper, a fuzzy logic approach is employed in the calculation of well losses. An advantage of the fuzzy logic approach is that it does not make any assumptions about the form of the well loss functionality and does not require initial estimates for the calculation of well losses. Results show that the fuzzy model is a practical alternative to the Rorabaugh technique, producing lower errors (mean absolute error, mean square error and root mean square error) relative to observed data, for the case presented, comparatively to the Rorabaugh model. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

A new analytical model to study the influence of weld on the vertical dynamic response of prestressed pipe pile          下载免费PDF全文

Wenbing Wu  Guosheng Jiang  Shenggen Huang  Guoxiong Mei  Chin Jian Leo 《国际地质力学数值与分析法杂志》2017,41(10):1247-1266

This investigation is concerned with the mathematical analysis of a viscoelastic prestressed pipe pile embedded in multilayered soil under vertical dynamic excitation. The pile surrounding soil is governed by the plane strain model, and the soil plug is assumed to be an additional mass connected to the pipe pile shaft by applying the distributed Voigt model. Meanwhile, the prestressed pipe pile is assumed to be a vertical, viscoelastic, and hollow cylinder governed by the one‐dimensional wave equation. Then, analytical solutions of the dynamic response of the pipe pile in the frequency domain are derived by means of the Laplace transform and impedance function transfer method. Subsequently, the corresponding quasi‐analytical solution in the time domain for the case of the prestressed pipe pile undergoing a vertical semi‐sinusoidal exciting force applied at the pile top is obtained by employing the inverse Fourier transform. Utilizing these solutions, selected results for the velocity admittance curve and the reflected wave curve are presented for different heights of the soil plug to examine the influence of weld properties on the vertical dynamic response of prestressed pipe pile. The reasonableness of the theoretical model is verified by comparing the calculated results based on the presented solutions with measured results. Copyright © 2017 John Wiley & Sons, Ltd.  相似文献   

Determination of the role of entrapped air in water flow in a closed soil pipe using a laboratory experiment          下载免费PDF全文

Takuhei Yamasaki  Hiromi Imoto  Shoichiro Hamamoto  Taku Nishimura 《水文研究》2017,31(21):3740-3749

Soil pipes, continuous macropores parallel to the soil surface, are an important factor in hillslope hydrological processes. However, the water flow dynamics in soil pipes, especially closed soil pipes, are not well understood. In this study, the water and air dynamics within closed soil pipes have been investigated in a bench‐scale laboratory experiment by using a soil box with an artificial acrylic soil pipe. In order to grasp the state of water and air within the soil pipe, we directly measured the existing soil pipe flow and air pressure in the soil pipe. The laboratory experiment showed that air in the soil pipe had an important role in the water flow in the closed soil pipe. When air entrapment occurred in the soil pipe before the soil matrix around the soil pipe was saturated with water, water intrusion in the soil pipe was prevented by air entrapped in the pipe, which inhibited the soil pipe flow. This air entrapment in the soil pipe was controlled by the soil water and air flow. Moreover, after the soil pipe flow started, the soil pipe was not filled completely with water even when the soil pipe was completely submerged under the groundwater table. The entrapped air in the soil pipe prevented further water intrusion in the soil pipe.  相似文献   

初始几何缺陷对UOE焊管屈曲压溃影响研究   总被引：1，自引：1，他引：0  

李杨  余建星  余杨  段晶辉  韩梦雪  李牧之  于佳晖 《海洋工程》2019,37(4):87-97

UOE焊管经过一系列成型工艺可以得到高质量的成型结果,但管道截面仍存在一定初始几何缺陷,这将对管道性能产生明显影响。通过试验测定X65钢在循环载荷下的力学性能,并利用有限元分析软件对UOE焊管成型全过程进行模拟,分析主要成型参数对管道屈曲压溃压力的影响。分别采用有限元模拟和试验测量方法确定管道截面初始几何缺陷分布情况,并采用余弦函数形式拟合几何缺陷。结果表明,扩径阶段芯轴数目将对缺陷形式产生影响,且实际厚壁UOE管道几何缺陷形式更接近梨形而非椭圆形。评估厚壁UOE管道性能时,近似认为截面形式为椭圆形可能发生过于保守的问题。  相似文献   

南海西沙西科1井层序地层格架与礁生长单元特征   总被引：3，自引：0，他引：3       下载免费PDF全文

朱伟林  王振峰  米立军  杜学斌  解习农  陆永潮  张道军  孙志鹏  刘新宇 《地球科学》2015,40(4):677-687

碳酸盐岩礁滩体系是南海海域重要的油气储层之一.南海西沙岛屿全取心的科学钻井——西科1井, 为南海碳酸盐岩礁滩体系的详细研究提供极好的条件.通过西科1井岩心的宏观描述及微观分析, 结合高分辨岩心扫描及大量分析测试结果, 对碳酸盐岩礁滩体系展开了精细研究.根据识别出的6个暴露面、2个淹没面, 将西科1井中中新世以来划分为9个三级层序.其中晚中新世黄流组和第四系乐东组为主要成礁期, 以海泛面和暴露面为标志, 将礁体归纳为淹没型生长单元和暴露型生长单元两大类, 暴露型又进一步细分为硬基底和软基底两类, 淹没型可细分为快速淹没和缓慢淹没两类.垂向上形成了极具特色的礁体组合, 即慢步礁(或淹没礁)、同步礁(加积礁)、快步礁(暴露礁).研究成果对于南海生物礁生长过程及碳酸盐岩礁滩储层勘探具有重要参考价值.   相似文献   

松软煤系地层深孔绳索取心钻探实践          下载免费PDF全文

张元清  孟庆伟  颜廷福  刘兴福 《探矿工程》2015,42(11):38-40，45

长春市高家窝棚—双泉眼矿区为松软煤系地层,采用绳索取心液动冲击回转钻进方法,选择加大钻孔孔壁与钻杆环状间隙的钻孔结构;经实验选择以粘土、共聚物、植物胶、铵盐、腐植酸钾、磺化沥青、聚丙烯酸钾等材料配制的冲洗液,并加强冲洗液的日常维护管理;配备离心式除泥机;套管丝扣连接处涂抹松香（粘结剂）,并用薄钢板焊接补强丝扣连接处,防止套管脱扣等技术措施,成功地完成了2个深孔的钻孔施工,终孔深度分别为1112.45 m（ZK6405孔）和1359.95 m（ZK3201孔）,岩心采取率达到100%,煤心样品没有燃烧破坏现象,较好地满足了地质的要求。  相似文献   

液力衡扭旋冲提速工具及其在达深16井的应用          下载免费PDF全文

李秋杰  王春华  李玉海  万发明  李欢欢 《探矿工程》2015,42(1):31-33，37

大庆油田深部地层岩石坚硬、研磨性强,运用常规手段钻进,单只钻头进尺少、寿命短且机械钻速较低。应用液力衡扭矩提速工具,有效解决了这些问题,显著提高了机械钻速和单只钻头的进尺。通过达深16井的现场试验证明,该工具能够使钻头的破岩方式在剪切的基础上附加机械冲击和高压水力脉冲,有效提高PDC钻头剪切岩层的效率,为深井提速提供了一种有效的手段。  相似文献   

庆深气田深层钻完井配套技术          下载免费PDF全文

韩福彬  杜敬安  王忠福  姜玉芳 《探矿工程》2015,42(12):18-22

自庆深气田徐深1井取得深层天然气勘探重大突破以来,大庆油田步入了油气勘探开发并举阶段。2004—2010年完成123口井,平均井深4118 m、钻井周期141 d,钻井技术水平较低。虽然开展提速技术攻关取得一定效果,但仍然不能满足天然气快速增储上产的需求,还存在着固井后井口带压问题,急需深入开展钻完井技术攻关。自2011年起,借鉴国内外深层提速技术成果,分开次、分层段针对岩性特点制定提速对策,通过优化井身结构、优选高效PDC钻头、实验并自研液动旋冲和涡轮等新型提速工具,大幅度提高了深井钻井技术水平,2011—2013年完成19口井,平均井深4075 m、同比缩短钻井周期48.6 d;针对井口带压问题,综合分析其产生因素,开展系列技术研究,形成了防气窜固井配套技术,为深层天然气快速增储上产提供了支持和保障。  相似文献   

低渗透成膜钻井液在贵州深部地热井中的应用          下载免费PDF全文

王虎  陈怡  段德培  吴晓兰  李勇  苏宁 《探矿工程》2015,42(4):13-15，20

贵州省碳酸盐岩地层分布广泛,溶洞、溶隙、裂隙发育。在地热深井钻进过程中,经常在热储层钻遇溶洞,出于储层保护目的,常常采取顶漏钻进措施。在贵州铜仁ZK2地热井热储层遇到此情况时,采用了低渗透成膜钻井液顶漏钻进,节约了钻探成本,同时能将岩屑及时排出,保证了钻井安全,为低渗透成膜钻井液在深部地热钻井中的应用提供了宝贵的经验。  相似文献   

绳索锤击取心浅钻技术在近海砂矿勘查中的应用          下载免费PDF全文

韩孝辉  龙根元  刘刚  孙水文 《探矿工程》2015,42(12):9-12

在海南岛东部滨浅海砂矿资源调查中,应用绳索锤击取心浅钻技术实施20 m浅钻,取得了较好的效果。实践证明,这种浅钻技术是获取浅层地质实物资料、验证地下信息推断与解释,最终圈定矿体、计算储量、评估品位的有效手段。介绍了这种结构简单、扰动较小的地质浅钻技术及其在生产中的应用。  相似文献