盘锦地区地下水位映震效能分析

盘锦地区深井水位观测始于上世纪七八十年代,观测资料连续可靠,在辽宁省及邻区发生的中强地震前有很好的前兆信息。通过研究盘锦地区深井水位的多年动态,分析典型震例,并利用基于GIS的地震分析预报系统等,探讨了水位变化和油田开采的关系,总结了盘锦地区地下水位的映震效能。     

深井水位记震能力用于地震预报的研究

深井水位记录地震波的能力反映了地下应力场的状况，而记震能力随时间的变化揭示了地下应力场状态随时间的变化。研究表明：当深井水位记震能力ＭＳＴ表现出超过一倍标准差σ的变化后，半年左右在其附近地区往往有中强以上地震发生。根据六年来的预报实践表明，深井水位记震能力是一种花钱较少、效果较好、应用广泛的地震预报前兆手段。     

用有序度研究深井水位记震能力

深井水位记震能力可作为一种预报地震的前兆手段，应用系统科学中的序度Ｒ来源深井水位记震能力，其工作结果：（１）深井水位记震能力所组成的系统表现为有组织系统；     

深井水位气压系数前兆信息探索

以深井水位气压效应的形成机制为出发点，阐述了地震前井孔气压系数异常变化的物理依据，并以新０４井为例，对其震前水位气压系数的异常变化进行了探索。     

2013年芦山MS7.0地震和2008年汶川MS8.0地震井水位同震变化的比较分析

以芦山、汶川地震震中为中心,选择了8个井点,对2个地震引起的井水位同震变化进行了比较,重点分析了3口同震变化反向的井点,即重庆的荣昌华江井、北碚柳荫井和四川的泸沽湖井。为使对比研究结果可靠,进一步收集了2011年3月11日日本9.0级地震、2012年4月11日苏门答腊北部海域8.6级地震引起的井水位同震变化资料。对汶川、芦山地震引起的同震体应变的计算结果显示：汶川地震时,荣昌华江井、北碚柳荫井和泸沽湖井水位同震变化与井点位置处的同震体应变一致,即位于同震体应变压缩区的井水位上升,位于体应变膨胀区的井水位下降;芦山地震时,3口井的水位同震变化与同震体应变不一致,表现出与日本、苏门答腊地震时相似的同震变化特征。     

深井水位的矿震效应ht

在系统收集与整理了1980年以来陶庄煤矿的矿震对鲁15井水位动态影响的资料基础上，研究了深井水位同震效应的特征．发现了深井水位的矿震前兆现象，讨论了深井水位矿震效应的物理机制．      

泄流量对动水位观测影响的分析

利用深井动水位观测资料预报地震,已经被国内外地震学家进行深入研究,并得到了许多珍贵的震例资料。从多年的观测实践认识到,观测装置系统对动水位记录地震信息量是关键环节,泄流量的调节也是提高动水位观测质量的重要因素。     

四川地区地下水位对汶川地震的同震效应

系统地清理、分析了四川地区2008年汶川地震时在测水位观测到的同震效应.结果显示:汶川地震的水位同震效应以阶跃变化中的阶升变化为主,同时兼有持续缓慢变化、潮汐畸变变化、无变化、脉冲变化和突跳式变化.研究表明:阶升、阶降井点在空间上分布不均匀,相对于震中位置的关联性不强,但距离震中越近,阶升的台项越多.震时水位变化幅度不...     

中国大陆井水位与水温动态对汶川M_S 8.0地震的同震响应特征分析

分析了汶川MS8.0地震在中国大陆引起的水位、水温同震变化特征,对比研究了2007年9月12日印尼苏门答腊MS8.5远震和汶川MS8.0近震在四川及其附近地区引起的水位、水温同震变化差异,结果表明:汶川地震在中国大陆引起的水位同震变化以上升为主,同时水位上升与下降的井点空间分布表现出一定的分区性;水位、水温同方向阶变的井点数比例高于两者反方向阶变井点数比例,当水位同震变化为振荡型时,水温以下降型为主;相对于远震,近震引起的水位、水温同震变化井点数量增加,无变化井点数量减少;所有井水位和大多数井水温同震阶变的方向都不因地震的远近、大小、震源机制或地震方位的变化而改变,个别发生水温同震升降方向变化的井点是由于水的自流状态和水位同震阶变由振荡转为阶变的改变所引起;水位同震升降性质受控于当地的地质构造环境和水文地质条件,而水温同震变化还与地震波引起的井孔中水的运动方式、水温探头放置的位置等因素有关,其机理更为复杂     

四川德阳白叁天然油气深井水位突降与地震的对应关系

本文介绍了白马深井水位的几项震俐资料。分析讨论了含天然气深井水位变化具有较好的反映地下深部信息的能力。认为选择产气量不大,其他条件适宜的气井,进行水位或气体压力变化观测有积极的意义。     

降雨对汤坑群井水位动态影响的剖析

本文详细调查汤坑盆地水文地质条件的基础上，系统分析了盆地内６口地震地下水动态观测井的水位年、月、日动态及其与相应时段的雨特征的关系，提出了该区深井承压水的水动力系统与水动态类型的多样性、井区降雨对不同频带的井水位动态影响的差异性与对不同井的水位动态影响的复杂性及降雨对深井水位动态影响是以水压力传导为主的认识与观点。     

Evaluation of Vertical Head Profiles in Water Production Wells during Pumping

In a recent field study, the performance of four production wells was evaluated. The intake of a vertical turbine test pump was set below the top of the screened interval of the wells due to anticipated drawdown. Water level sounding tubes were welded to the well casing at various depths in each well. Drawdown data collected at various depths were used to evaluate the vertical head distribution in the wells under various pumping stresses. A direct relationship was observed between the head loss and the location of the pump intake in the production wells. A vertical head profile developed, suggesting that the location of the pump intake controlled the location of water production from the aquifer. The head loss in the wells observed during pumping was directly proportional to well discharge and annulus size between the well casing and the vertical turbine pump shaft. The pressure differences that developed in the wells created increased drawdown in water level sounding tubes installed deep in the wells compared to the total drawdown observed in the production wells. Certain implications should be considered based on the evaluation of the data obtained from this study. Because water management decisions are made using well test data, the quality of the data is crucial. In instances where well performance is evaluated using water level data collected from water level sounding tubes that are located close to a pump intake (in this case deep in the well), it should be recognized that well performance could be underestimated.     

深井热水开采对豫01井水位影响的探讨

河南省濮阳地区地下热水的开采对处于同水层的地震观测井—豫01井水位观测产生了严重的干扰影响。豫01井水位自1996年9月出现下降变化以来,其水位动态一直受到大家的关注。十几年来,地震界专家学者对有可能影响该井水位动态的诸多因素逐一进行了追踪研究。认为豫01井自1996年9月至今水位变化与中原油田抽水、注水、采油无关;其...     

鲁豫交界地区深井水位持续大幅度下降原因分析

鲁豫交界地区豫01、11井和鲁27井等3口地震观测深井的水位于2006年后出现了准同步的异常下降变化,下降幅度3 ～12m不等.经调查落实,发现该地区近年来地热开采活动日益增强,开采量逐年增大,并且开采层与异常井水位观测层同属于奥陶系热储层.为此,本文依据聊城-兰考断裂带附近区域的水文地质构造特征,建立了三维地下水流动模型,基于周边地热开采量数据和相关含水层参数,运用有限差分方法计算了地热开采所引起的区域水位降落漏斗,并分析了水位下降异常的时间演化和空间分布特征.结果显示,聊城-兰考断裂带附近区域自1995年开始地热开采活动以来,其逐年增加的地热开采量与地震观测井水位的下降幅度之间存在较好的对应关系,分析认为鲁豫交界地区3口深井水位的准同步异常下降与周边地热开采活动有关.     

Co-seismic Water Level and Temperature Responses of Some Wells to Far-Field Strong Earthquakes and Their Mechanisms

The observation of water temperature in deep wells has been carried out for more than 20 years in China.However,study on the mechanism of water temperature response to earthquakes is inadequate.During the study of the co-seismic response characteristics of water level and temperature in 121 wells within the China subsurface fluid monitoring network at the time of the December 26,2004,M-S8.7 Indonesia earthquake,we found regular response characteristics,that is,when the water level in a deep well oscillates,the water temperature in the same well will mostly experience a cycle from dropping to restoration at the same time.The process will continue for dozens of minutes to several hours.In order to confirm the observed phenomenon,we collected the digital water level and temperature observation data for 39 far-field strong earthquakes from the Tangshan well in Hebei Province(with the data set beginning in 2001).The same response characteristics were observed.Based on the analysis of the influencing factors that may cause the water temperature drop,the authors suggest the gas escape mechanism for co-seismic water temperature drop and posit two main factors that influence the water temperature drop during the process of gas escape.Finally,the authors provide a rational explanation of some observed phenomena based on the mechanism.     

The Hydraulic Effects of Lost Circulation and the Implications for Contaminant Migration During Drilling

The impact of lost circulation during rotary drilling near an existing monitoring well cluster was evaluated by periodic measurements of water levels and contaminant concentrations at the well cluster. Due to regulatory concerns, changes in water levels or VOC concentration in the well cluster during drilling would trigger monitoring well redevelopment. The borehole was drilled approximately 30 feet northeast of four nested monitoring wells that screen Devonian and Silurian carbonate bedrock at depths of 15, 60, 130, and 190 feet. Following complete circulation loss at depths of 177 and 1 S3 feet in the borehole, a rapid decrease in water levels was observed in the upper three monitoring wells. The water level in the well that was screened through the lost circulation zones increased slightly.
Decreasing water levels in formations located above the point of circulation loss appear to occur in response to a sudden decrease in borehole fluid pressure caused by the flow of drilling fluid into the formation. The relative contribution of contaminated formation water lo the borehole can be estimated by using the time-drawdown relationship and estimates of transmissivity. At the point of circulation loss, significant dilution of contaminant concentrations occurs from the loss of drilling fluid into the contaminated zone. Contaminated formation water entering the borehole during periods of complete lost circulation may mobilize contaminants from upper lo lower formations. Lost circulation into a formation would be signaled by a water level increase in monitoring wells. The wells would subsequently require development to remove the volume of fluid lost to the formation, including both drilling fluid and contaminated formation water. Monitoring wells exhibiting declining water levels following lost circulation would not require development since drilling water has not entered the zones screened by these wells.     

三峡井网地下流体动态与映震能力的初步分析

系统分析了三峡井网 8口井水位、4口井水温和 4个井台土氡 2 0 0 1年的观测数据 ,建立了各个测项的正常动态 ,并检验了其各自的映震能力。结果表明 ,8口井水位均有固体潮显示 ,其对地壳体应变的响应灵敏度为 10 - 9～ 10 - 10 体应变 /mm。井水位大多有气压效应 ,并受一定程度的降雨干扰。 4口井的水温动态相对平稳 ,日变幅一般为千分之几度。 4个井台的土氡动态起伏较大 ,变化范围在几到几十Bq/L之间。在 2 0 0 1年 10月 16日秭归县梅家河ML3 6地震前 ,有 6口井水位、1口井水温和 1个井台的土氡有异常显示 ,表明三峡井网具有较强的映震能力     

珠江口盆地深部基底地层的地震时深转换研究

盆地深部基底的地震解释需要时深尺.而钻遇基底的探井通常很少且仅揭示基底顶部,致使常规VSP时深转换曲线难以达到基底研究所涉及的深度.为此本文提出深部下延段校正的VSP时深转换方法,即用深井和钻遇基底井VSP数据与深反射地震、双船折射地震和重磁数据在深部下延段选取控制点的时深数据,重新拟合时深转换的二次多项式,使其可用于...     

Groundwater-level Changes Due to Pressure Gradient Induced by Nearby Earthquakes off Izu Peninsula, 1997

Anomalous water level changes were observed at two wells associated with seismic swarm activity off Izu Peninsula on March, 1997. These are coseismic water level drops followed by gradual postseismic water level rise at the time of large earthquakes during the swarm activity. The post-seismic water level rises, which can be fitted by an exponential function with a time constant of about six hours, are explained in terms of the horizontal pressure diffusion due to the pressure gradient in the aquifer induced by the coseismic static strain.