深井水位对固体潮和气压的响应   总被引：1，自引：0，他引：1  

张昭栋  郑金涵 《地震研究》1993,16(4):431-439

本文以体应变固体潮对深井水位影响的偏微分方程为基础，考虑到含水层与井孔之间相互渗流的边界条件，用叠加原理、冲量定理的分离变量等方法得出了方程的解。把水井含水层的参量给予一些可能的值，通过数值计算讨论了水井固体潮系数、位相滞后和含水层参数之间的关系，解释了井水位对固体潮响应的位相滞后现象。结果表明，井孔的半径、含水层的孔隙度及固体骨架的体压缩系数愈大，含水层的导水系数愈小，则水井水位的固体潮系数愈小  相似文献   

Formation of regolith-collapse sinkholes in southern Illinois: Interpretation and identification of associated buried cavities     

S. V. Panno  C. P. Wiebel  P. C. Heigold  P. C. Reed 《Environmental Geology》1994,23(3):214-220

Three regolith-collapse sinkholes formed near the Dongola Unit School and the Pentecostal Church in the southern Illinois village of Dongola (Union County) during the spring of 1993. The sinkholes appeared over a three-month period that coincided with development of a new municipal well. The new well was drilled through clay-rich, valley-fill sediment into karstified limestone bedrock. The piezometric surface of the limestone aquifer is above land surface, indicating the presence of an upward hydraulic gradient in the valley and that the valley fill is acting as a confining unit. Pumping during development of the well lowered the piezometric surface of the limestone aquifer to an elevation below the base of the valley fill. It is hypothesized that drainage of water from the sediments, the resulting loss of hydrostatic pressure and buoyant force in overlying sediments, increased intergranular pressure, and the initiation of groundwater flow toward the well resulted in rapid sediment transport, subsurface erosion, and collapse of the valley-fill sediment. The sinkholes follow an approximately east-west alignment, which is consistent with one of the two dominant alignments of passages of nearby joint-controlled caves. A constant electrode-separation resistivity survey of the school playground was conducted to locate areas that might contain incipient sinkholes. The survey revealed a positive resistivity anomaly trending N75E in the southern part of the study area. The anomaly is linear, between 5 and 10 m wide, and its trend either intersects or is immediately adjacent to the three sinkholes. The anomaly is interpreted to be a series of pumping-induced cavities in the valley-fill sediments that formed over a preexisting crevice in the karstified bedrock limestone.  相似文献   

树分类器在测井岩性评价中的应用          下载免费PDF全文

潘懋  马莉  魏至峰 《地质科学》1993,(2):193

 利用测井资料进行岩性定量识别,分类方法的设计是决定分类结果好坏的关键。本文讨论了树分类器与产生式规则相结合的方法在岩性分类中的应用。利用数据完整的测井曲线参与树分类器的学习、判别工作,用树分类器进行岩性的“逐级识别”,不完整的特征交由定性规则处理,既实现了岩性的细分,且保证了分类的精度。  相似文献   

2002年10月以来昌黎井水位趋势上升分析   总被引：2，自引：0，他引：2  

张素欣  张子广  刘俊明  蔡连菊 《华北地震科学》2003,21(4):19-22

2002年10月昌黎井井口装置进行改造,改造之后排水口变小,引起了水位趋势上升变化.进入2003年4月以来,该井水位继续上升,无转折迹象.与往年同期比较,2002年10月以来的上升呈现上升幅度大、上升速率快的特点.由此对"改造出水装置引起水位上升"提出疑问,该井水位目前上升幅度大和上升速率快,到底是否地震异常?针对这一关键问题,做了以下分析工作地下水储量变化对井水位升降的影响;同一观测井多个测项的对比分析;解释了井孔出水管变细引起水位上升幅度大、上升速率快的机理,认为是地震短临异常的可能性较小.  相似文献   

Analysis of aquifer heterogeneity within a well capture zone,comparison of model data with field experiments: A case study from the river Wiese,Switzerland     

Christian Regli  Martin Rauber  Peter Huggenberger 《Aquatic Sciences - Research Across Boundaries》2003,65(2):111-128

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测井曲线标定有机碳方法在苏北盆地的应用     

顾红英 《江苏地质》2004,28(3):166-169

测井曲线标定有机碳技术方法是一种不同于传统地球化学测试得到的有机碳方法，它根据烃源岩内有机质的含量在测井曲线上具有一定的特征响应，通过地球物理测井手段鉴别与提取这些特征属性，再利用测井曲线标定的有机碳含量关系式进行计算，从而得到准确的有机碳含量。这种方法既简便易行又准确可靠，与传统地球化学测试得到的有机碳方法具有良好的对应性。通过对苏161井阜四段、苏169井阜三段烃源岩测井标定有机碳含量与实测值的对比性研究，表明在苏北盆地用测井资料计算的有机碳来补充取心资料的不足，从而对该地区地下油气进行分析具有切实的可行性和较好的适用性。  相似文献   

昌平台Sacks体应变仪观测曲线年变现象成因研究   总被引：3，自引：0，他引：3  

张凌空 《中国地震》2005,21(2):254-259

本文系统地研究了北京昌平台Sacks体应变仪观测曲线年动态变化的基本规律，结合井水位、抽水和降雨等实际观测资料，分析后认为，台站附近农田机井季节性抽水和地下水的自然补给是造成体应变年变现象的根本原因，并探讨了体应变与井水位的定量关系和物理机制，同时对地震预测中所关心的“破年变”问题也进行了探讨。  相似文献   

Isotope measurements and ground water flow modeling using MODFLOW for understanding environmental changes caused by a well field in semiarid Brazil     

Luiz Alberto Ribeiro Mendonça  Horst Frischkorn  Marlúcia Freitas Santiago  Josué Mendes Filho 《Environmental Geology》2005,47(8):1045-1053

Measurements of the environmental isotopes carbon-14 and oxygen-18 and of the electrical conductivity in ground water, together with MODFLOW-88 (DOS) simulations of pumping tests, were used to achieve a detailed understanding of the functioning of an aquifer in the area of a well field. The methodology was applied in the sedimentary basin of the Cariri region, in the south of Ceará State in Brazil. Localized hydraulic connections between adjacent aquifer units could be detected, and mixing ratios for the contributions from the units involved were determined. Cone of depression simulations for a three-year drought period revealed well interference and a drastic lowering of the piezometric level, thereby explaining the hydrogeologic changes and transformations in vegetation that were observed in the area of the well field. The combined use of the modeling tools and the geochemical field observations is shown to provide more detailed insight into the conceptual model of the groundwater flow system.  相似文献   

Non-Darcian flow in a single confined vertical fracture toward a well     

Zhang Wen  Guanhua Huang  Hongbin Zhan   《Journal of Hydrology》2006,330(3-4):698-708

Non-Darcian flow towards a well which fully penetrates a confined single vertical fracture is presented in this paper on the basis of the Izbash equation. We have obtained semi-analytical solutions for non-Darcian flow by using the Boltzmann transform and developed the non-Darcian flow well functions for cases with and without the effect of wellbore storage. The results show that the non-Darcian flow type curves are more or less deviated from the Darcian flow type curve. The non-linear effect is mainly attributable to the turbulent factor, v, a dimensionless parameter related to the pumping rate, the fracture aperture, the fracture thickness, and two constants k′ and n used in the Izbash power-law. The non-linear effect appears to be less sensitive to the power-law index, n. When excluding wellbore storage, the well function at early times is proportional to v^−1/(n−1)u^−n/(n−1), where u is a dimensionless term inversely proportional to time; whereas the well function at late times is approximated as , where A₀(n) is a finite term depending on n. When considering wellbore storage, drawdowns inside the well with different v values approach the same asymptotic value at small times, and the effect of wellbore storage is only found at the early stage of pumping.  相似文献   

测井在天然气水合物勘探与评价中的应用     

陆敬安 《南海地质研究》2006,(1):71-84

测井是水合物深入勘探阶段一钻探阶段的必要手段，已得到较好应用。文章综合介绍和分析了ODP204航次、加拿大西北马更些河三角洲地区Mallik5L-38井、IODP311航次及日本南海海槽等较新的水合物钻探调查的测井方法与技术，重点分析了核磁测井、电磁波测井及偶极横波测井等测井新技术在水合物勘探与评价中的应用，对测井方法在水合物勘探中存在的问题进行了讨论。  相似文献