Confirmed faecal pollution to bore well waters of Mysore city     

D. Nagaraju  J. C. V. Sastri 《Environmental Geology》1999,38(4):322-326

 Water-borne infections are the most common causes of infectious diseases in developing countries, often resulting from the lack of a protected water supply, a faulty water-supply system or improper sewage disposal. A recent study of 107 samples from bore wells of Mysore city has revealed that 51 samples (47.66%) contain Nitrate greater than 45 ppm, an indication that the water would be harmful for drinking. Out of 51 samples tested for faecal pollution, using a H₂S-strip test, 37 samples turned black and these were subjected to microbial identification. Out of these 37 samples, 63 H₂S producing strains were isolated and the H₂S producing organisms are Klebsiella ozaene;Klebsiella pneumoniae;Proteus mirabilis;Proteus vulgaris;Salmonella sp. and Citrobacter freundi. The frequency of occurrence of the above-mentioned six micro-organism strains are as follows: Proteus mirabilis (19);Proteus vulgaris (14);Citrobacter freundi (13);Salmonella sp. (8);Klebsiella pneumoniae (5); and Klebsiella ozaene (4). Klebsiella and Proteus are known to cause urinary infection and Salmonella intestional infection. Received: 7 September 1998 · Accepted: 10 November 1998  相似文献   

陕北油田二开井段提下钻遇阻原因分析与对策     

王天宝  刘锋  陈亮  厉磊 《地质与勘探》1999,35(4):62-63

陕北油石二开井段遇阻的原因为泥岩的水化膨胀和孔隙性砂岩的泥饼沉积。对策主要有物理方法（如短程起下钻、加大排量等） 、化学方法（加入强抑制剂ＦＡ３６７、加入ＧＰＳ,提高泥饼质量） 等。  相似文献   

制作小圆井素描展开图的简便方法     

罗俊升 《地质与勘探》1999,35(5)

从几何分析出发,结合实例介绍了制作小圆井素描展开图的简单方法,其精度可达地质要求  相似文献   

油井参数声传输及井下发射控制     

孙晓光  刘广智  冯遵城  路德明  李中玉  龙洪彬  马东升 《中国海洋大学学报(自然科学版)》1999,(4)

介绍一种油井井下参数（压力、温度）无线测试的数据信息传输方法及井下发射装置低功耗控制电路。在不停产的情况下,对井下参数进行长期监测,获得确切可信的第一手资料以便对油井施行相应的增产措施。  相似文献   

Depositional environments of well‐sorted detrital limestone from the Minatogawa Formation in the southern part of Okinawa Island,the Ryukyu Archipelago,Japan          下载免费PDF全文

Kazuhiko Fujita  Kayo Aruga  Marc Humblet  Koichi Nagai 《Island Arc》2018,27(3)

Well‐sorted detrital limestone is one of the typical lithofacies of the latest interval of the Pleistocene Ryukyu Group, which is exposed in the Ryukyu Archipelago in southwestern Japan. The depositional environments of the limestone are interpreted to be extremely shallow and to include back‐reef lagoons or moats and subaerial sand dunes. However, detailed micropaleontological analyses have not been performed on this limestone. In this study, the interpretation of the depositional environments and paleo‐water depths was improved by quantitative examination of foraminiferal assemblages for the well‐sorted detrital limestone of the Minatogawa Formation in the southern part of Okinawa Island. Thin sections of limestone collected from the Minatogawa (Horikawa) quarry were subjected to sedimentological and foraminiferal analyses. Comparison with modern foraminiferal distribution within the Ryukyu Archipelago indicates that back‐reef and fore‐reef dwelling foraminifers characterize the fossil assemblages from the well‐sorted detrital limestone (bioclastic grainstone). Three ratios of indicator foraminiferal taxa (ratios of back‐reef to fore‐reef taxa, planktonic foraminifers to Amphistegina lobifera and Amphistegina lessonii, and Calcarina gaudichaudii to other Calcarina species), as well as multivariate analyses suggest that the well‐sorted detrital limestone was deposited in fore‐reef setting shallower than 40 m in water depth. A comparable depth range was reconstructed from the coral assemblage in the associated coral limestone, suggesting that the Minatogawa Formation was deposited in a gently inclined ramp setting with patch reefs and/or fringing reefs. Stratigraphic changes in paleo‐water depth, together with evidence of several unconformities associated with paleosol layers suggest that there were repeated transgressions and regressions, with an amplitude up to several tens of meters, when the Minatogawa Formation was deposited.  相似文献   

赵各庄井水位水温演化特征及其成因分析     

韩孔艳  邢成起  崔博闻  孔来顺  孙小入 《地震》2019,39(3):178-186

平谷赵各庄井深200 m, 观测含水层为182 m以下的全井段, 是浅层冷水和深层热水的混合水。 受开采及降雨影响, 水位、 水温长趋势及年动态具有同步协调性变化, 地下水开采使井筒内冷水比例变小, 水位下降, 水温上升; 降雨渗入补给使流入观测井筒内冷水占比例变大, 水位上升, 水温下降, 但雨季结束, 井筒内冷水流入量变少, 井水温逐渐回升。 气压和固体潮使井筒与含水层间有水流运动, 水位出现周期性波动, 从而改变井筒内冷热水比例, 引起水温周期性变化的次生效应, 两者有短期同步协调变化。 不同种干扰因素造成了不同周期的变化影响, 在排除干扰, 提取地震异常信息时, 应选用不同方法及取样周期进行分析。  相似文献   

河北赤城井水温对远场大震的响应特征研究     

尹宏伟  梁丽环  韩文英  李凤  刘静 《地震地磁观测与研究》2019,40(5):93-100

在河北赤城井井下30 m、53 m、58 m处分别安装了3个温度传感器,进行水温微动态观测。通过对2004年12月以来全球发生的22次M_S≥8.0地震时赤城井不同深度水温观测数据的变化进行研究发现,井下30 m处水温均无明显同震变化;而7次大震时53 m、58 m处水温有明显的同震变化,53 m处水温同震初始变化形态均为上升,58 m处均为下降。同时,对水温变化机理进行探讨发现,井下30 m处水温日变幅度偏大是记录不到地震的主要原因;水温同震初始变化是由井孔水体对流引起的,53 m处水温同震初始变化形态均为上升是由于该处位于负温度梯度带,井孔中水体受震荡激发而加速对流与掺混是导致58 m处水温同震初始下降的主要原因,赤城井水温同震初始变化的后效恢复过程为热传导作用的结果。  相似文献   

Fluvial to bay sequence stratigraphy and seismic facies of the Cretaceous to Paleogene successions in the MITI Sanriku‐oki well and the vicinities,the Sanriku‐oki forearc basin,northeast Japan          下载免费PDF全文

Osamu Takano  Takashi Tsuji 《Island Arc》2017,26(4)

This paper describes the significant depositional setting information derived from well and seismic survey data for the Upper Cretaceous to Lower Eocene forearc basin sediments in the central part of the Sanriku‐oki basin, which is regarded as a key area for elucidating the plate tectonic history of the Northeast Japan Arc. According to the results of well facies analysis utilizing cores, well logs and borehole images, the major depositional environments were of braided and meandering fluvial environments with sporadically intercalated marine incursion beds. Seismic facies, reflection terminations and isopach information provide the actual spatial distributions of fluvial channel zones flowing in a north–south trending direction. The transgression and regression cycles indicate that the Upper Cretaceous to Lower Eocene successions can be divided into thirteen depositional sequences (Sequences SrCr‐0 to SrCr‐5, and SrPg‐1 to SrPg‐7). These depositional sequences demonstrate three types of stacking patterns: Types A to C, each of which shows a succession mainly comprising a meandering fluvial system, a braided fluvial system with minor meandering aspects in the upper part, and major marine incursion beds in the middle part, respectively, although all show an overall transgressive to regressive succession. The Type C marine incursion beds characteristically comprise bay center and tidal‐dominated bay margin facies. Basin‐transecting long seismic sections demonstrate a roll up structure on the trench slope break (TSB) side of the basin. These facts suggest that during the Cretaceous to Eocene periods, the studied fluvial‐dominated forearc basin was sheltered by the uplifted TSB. The selective occurrences of the Type C sequences suggest that when a longer‐scale transgression occurred, especially in Santonian and early Campanian periods, a large bay basin was developed, creating accommodation space, which induced the deposition of the Cretaceous Kuji Group along the arc‐side basin margin.  相似文献   

河北省数字水位短临异常特征研究——以2016年唐山4.2级地震为例     

尹宏伟  梁丽环  韩文英  李凤  刘静 《地震地磁观测与研究》2017,38(4):119-125

2016年9月10日河北唐山发生M_S 4.2地震,以该震为例,研究河北省地下流体观测井水位震前异常变化特征。结果表明：①震中区域观测井水位异常变化形态一般为缓变型,震中外围观测井水位异常变化形态一般为骤变型;②距离震中越近,观测井水位异常出现越早,异常持续时间越长;③临近地震震中时,观测井水位异常有从震中向外围扩散的趋势;④观测井水位异常最大幅度与井震距关系不大。  相似文献   

江苏盐城盐纺井地球化学异常信息提取及机理分析     

祝涛  沈红会  李鸿宇  田韬  缪阿丽  叶碧文 《中国地震》2019,35(4):643-653

依据江苏省盐城市纺织厂井Ca²⁺和Cl^-月均值浓度,利用从属函数和自适应阈值法对该井进行了地球化学异常信息提取与分析;结合波速比和地磁谐波振幅比数据,利用膨胀扩容模式开展了映震机理讨论。结果表明,2008～2016年Ca²⁺浓度出现6次从属函数异常和5次自适应阈值异常,Cl^-浓度出现4次从属函数异常和5次自适应阈值异常,较好地对应了台站200km范围内M_L≥4.0的地震。此外,根据波速比、地磁谐波振幅比和该井地下水地球化学成因等分析结果,判断Ca²⁺、Cl^-浓度在震前的快速上升与深部流体上涌有关。  相似文献