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1.
Elastic and electromagnetic waves are commonly used to investigate various soil characteristics. The goal of this study is to estimate the elastic moduli and the void ratio based on both the compressional and shear wave velocities, and the electrical resistivity measured by field velocity resistivity probe (FVRP). The compressional and shear waves are measured by piezoelectric disk elements and bender elements installed at the end of the FVRP frame tip. The electrical resistivity is determined by the electrical resistivity probe installed at the tip of the FVRP frame. The FVRP tests are carried out in a clay–sand mixture prepared in a calibration chamber and in silty sand to silty clay soils in the field. The elastic waves and electrical resistivity are measured at every 1 cm. The field tests are carried out at a depth of 6–20 m, at 10 cm intervals, at the Southern coastal area of the Korean peninsula. The measured data are converted into the constraint and shear moduli based on the elastic waves. Void ratios are evaluated based on the elastic wave velocities and the electrical resistivity, and these void ratios match the volumetric void ratio well. This study suggests that the FVRP may effectively determine the elastic moduli and void ratio. 相似文献
2.
Amirali Mostafavi Moghadam Abbas Ghalandarzadeh Majid Moradi Ikuo Towhata Pouria Hajialikhani 《Bulletin of Earthquake Engineering》2011,9(4):1259-1288
This research is to study the efficiency of displacement reducer fuses, installed behind the caisson quay walls for controlling
the dynamic backfill thrust and minimizing the displacement, settlement and tilting of the walls. For this purpose, two types
of fuses, Displacement Reducer Panels (DRP) and Displacement Reducer Elements (DRE), were constructed and installed behind
the wall. The DRPs were constructed by hollow Polypropylene sheets to reproduce elastoplastic and plastic mechanical behaviors.
The DREs were cylindrical stainless-steel dampers, working upon friction mechanism that can reproduce perfect plastic behavior.
Here, two series of shaking table 1-g tests were performed with DRP and DRE applications. In this regard, different mechanical
behaviors and capacities were considered for fuses against demand thrusts of backfill in order to compare the mitigation tests
with no-mitigation cases. Harmonic base motions with constant amplitude and constant frequency were used in the model test.
The foundation soil and the backfill soil were constructed with the relative densities of 85 and 25%, respectively, to reproduce
non-liquefiable base layer and loose backfill situations in the model, respectively. The results showed remarkable reduction
in kinetic energy, dynamic backfill thrust and consequently seaward movement, settlement and inclination of the caisson quay
wall in case of using fuses with plastic behaviors behind the wall. 相似文献
3.
Michael J. Truex Vince R. Vermeul David T. Adamson Mart Oostrom Lirong Zhong Rob D. Mackley Brad G. Fritz Jake A. Horner Tim C. Johnson Jonathan N. Thomle Darrell R. Newcomer Chris D. Johnson Michal Rysz Tom W. Wietsma Charles J. Newell 《Ground Water Monitoring & Remediation》2015,35(3):34-45
Heterogeneity of hydraulic properties in aquifers may lead to contaminants residing in lower‐permeability zones where it is difficult to deliver remediation amendments using conventional injection processes. The focus of this study is to examine use of a shear‐thinning fluid (STF) to improve the uniformity of remedial amendment distribution within a heterogeneous aquifer. Previous studies have demonstrated the significant potential of STFs for improving remedial amendment delivery in heterogeneous aquifers, but quantitative evaluation of these improvements from field applications is lacking. A field‐scale test was conducted that compares data from successive injection of a tracer in water followed by injection of a tracer in an STF to evaluate the impact of the STF on tracer distribution uniformity in the presence of permeability contrasts within the targeted injection zone. Data from tracer breakthrough at multiple depth‐discrete monitoring intervals and electrical resistivity tomography (ERT) showed that inclusion of STF in the injection solution improved the distribution of the injected fluid within the targeted treatment zone. One improvement was a reduction in the movement of injected fluids through high‐permeability pathways, as evidenced by slower breakthrough of tracer at monitoring locations where breakthrough in baseline tracer‐only injection data was faster. In addition, STF‐amended injection solutions arrived faster and to a greater extent in monitoring locations within low‐permeability zones. ERT data showed that the STF injection covered a higher percentage of a two‐dimensional cross section within the injection interval between the injection well and a monitoring well about 3 m away. 相似文献
4.
在浅水环境中,利用频率域海洋可控源电磁法探测油气藏薄层面临着挑战,这是因为空气波支配着电磁响应而它只含有少量海底电阻率结构的信息.本文研究了空气波对时间域可控源电磁(CSEM)响应的影 响. 空气波到达时间取决于海水深度.在浅水区空气波到达早,而在深海水区空气波到达晚,空气波与来自深部电阻体的电磁波出现在不同时间段.虽然在中等深度的海水区空气波和来自深部电阻体的电磁信号几乎同时到达,但与不含有油气藏的背景模型相比,仍可以看到明显的异常.浅水区勘探的好处在于可以使用表面拖曳系统. 相似文献
5.
New Methods for Modeling Laterolog Resistivity Corrections 总被引：1，自引：1，他引：0
Jadwiga Anna Jarzyna Adam Cichy Dezső Drahos Attila Galsa Maria Joanna Bała Andrzej Ossowski 《Acta Geophysica》2016,64(2):417-442
The paper presents methods for laterolog response modeling. In Coulomb’s charges method, Laplace’s equation is solved for the electric field distribution in rock medium with internal boundaries between different resistivity layers. There, the boundary problem is reduced to Fred-holm integral equation of the second kind. The second method uses a finite element array to model apparent resistivity from laterolog. The task is treated as DC problem and the Laplace equation is solved numerically. The presented methods were applied to borehole data covering a typical stratigraphie section of the Fore-Sudetic Monocline in southwestern Poland. Apparent resistivity was calculated using the Coulomb’s charges method and alternatively modeled using a finite element method which gave similar results. Then, a series of linear corrections for borehole, shoulder bed, and filtration effects for apparent resistivity obtained by the Coulomb’s charges method demonstrated the feasibility of calculating true resistivity of virgin and invaded zones. The proposed methods provide a flexible solution in modeling which can be adapted to other logs. 相似文献
6.
The use of electrical resistivity surveys to locate karst conduits has shown mixed success. However, time‐lapse electrical resistivity imaging combined with salt injection improves conduit detection and can yield valuable insight into solute transport behaviour. We present a proof of concept above a known karst conduit in the Kentucky Horse Park (Lexington, Kentucky). A salt tracer solution was injected into a karst window over a 45‐min interval, and repeat resistivity surveys were collected every 20 min along a 125‐m transect near a monitoring well approximately 750 m downgradient from the injection site. In situ fluid conductivity measurements in the well peaked at approximately 25% of the initial value about 3 h after salt injection. Time‐lapse electrical resistivity inversions show two broad zones at the approximate conduit depth where resistivity decreased and then recovered in general agreement with in situ measurements. Combined salt injection and electrical resistivity imaging are a promising tool for locating karst conduits. The method is also useful for gaining insight into conduit geometry and could be expanded to include multiple electrical resistivity transects. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
7.
油层注入聚合物溶液后,电阻率测井响应发生与水驱不同的变化特征,严重影响水淹层测井评价的效果。本文首先分析了聚合物溶液的导电性质,其次按照聚合物驱油层不同施工流程开展岩电实验研究,分析不同驱替阶段的岩石电阻率的变化特征。并对比分析聚合物驱与水驱油层电阻率测井响应的差异。结果表明,不同聚合物驱替饱含油岩心过程,岩心电阻率随饱和度变化呈现"w"型或"S"型和单调下降的形态;清水聚合物驱油层电阻率测井响应呈现弱、未水淹的特征;污水聚合物驱油层电阻率测井响应呈现与污水水驱相似的变化特征。 相似文献
8.
H. Frank Morrison Yoram Shoham G. Michael Hoversten Carlos Torres-Verdín 《Geophysical Prospecting》1996,44(6):963-986
Sedimentary rocks beneath the Columbia River Basalt Group are recognized as having potential for oil and gas production, but the overlying layered basalts effectively mask seismic reflections from the underlying sediments. Four electromagnetic (EM) methods have been applied on profiles crossing Boylston Ridge, a typical east–west trending anticline of the Yakima Fold Belt, in an attempt to map the resistivity interface between the basalts and the sediments and to map variations in structure and resistivity within the sediments. The EM surveys detected strong variations in resistivity within the basalts, and in particular the continuous magnetotelluric array profiling (EMAP) revealed resistivity lows beneath the surface anticlines. These low resistivity zones probably coincide with fracturing in the core of the anticlines and they appear to correlate well with similar zones of low seismic velocity observed on a nearby seismic profile. The controlled-source EM surveys (in-loop transient, long-offset transient, and variable-offset frequency-domain) were designed in anticipation of relatively uniform high resistivity basalts, and were found to have been seriously distorted by the intrabasalt conductors discovered in the field. In particular, the resistivity sections derived from 1D inversions were found to be inconsistent and misleading. The EMAP survey provided the most information about the subsurface resistivity distribution, and was certainly the most cost-effective. However, both controlled-source and EMAP surveys call for accurate 2D or 3D inversion to accommodate the geological objectives of this project. 相似文献
9.
本文提出了一种计算注聚合物井井下温度分布的方法,该方法视井筒内的聚合物溶液为非牛顿幂律流体,考虑注入流体在井筒中同一截面上的速度变化,根据聚合物溶液在多孔介质中的流变性,依据广义达西定律求取渗流速度,基于能量守恒方程建立柱坐标系下注聚合物井井筒内流体、注入层及围岩的二维温度场模型.通过合理的边界条件,将三部分模型耦合起来,采用交替方向半隐式有限差分法求解建立的井下温度场模型.考查了注入量、注入时间、幂律指数和稠度系数、注入液温度等因素对井下温度场分布的影响,结果表明,当注入的聚合物溶液温度低于注入层的原始温度时,随注入量和注入时间的增大以及粘度的减小,注入层的温度降低;注入聚合物溶液温度与注入层原始温度差越大,注入层处的温度剖面异常越明显.本文数值计算结果可用于指导注聚合物井的井温测井应用. 相似文献
10.
Craig E. Divine Jesse Wright Michelle Crimi J.F. Devlin Michael Lubrecht Jack Wang Jeff McDonough Michael Kladias Jesse Hinkle Allison Cormican Trevor Osorno Blossom N. Nzeribe Fiona Laramay Daniel Ombalski Kathleen Gerber Hunter Anderson 《Ground Water Monitoring & Remediation》2020,40(3):42-54
The horizontal reactive media treatment well (HRX Well®) uses directionally drilled horizontal wells filled with a treatment media to induce flow-focusing behavior created by the well-to-aquifer permeability contrast to passively capture proportionally large volumes of groundwater. Groundwater is treated in situ as it flows through the HRX Well and downgradient portions of the aquifer are cleaned via elution as these zones are flushed with clean water discharging from the HRX Well. The HRX Well concept is particularly well suited for sites where long-term mass discharge control is a primary performance objective. This concept is appropriate for recalcitrant and difficult-to-treat constituents, including chlorinated solvents, per- and polyfluoroalkyl substances (PFAS), 1,4-dioxane, and metals. A full-scale HRX Well was installed and operated to treat trichloroethene (TCE) with zero valent iron (ZVI). The model-predicted enhanced flow through the HRX Well (compared to the flow in and equivalent cross-sectional area orthogonal to flow in the natural formation before HRX Well installation) and treatment zone width was consistent with flows and widths estimated independently by point velocity probe (PVP) testing, HRX Well tracer testing, and observed treatment in downgradient monitoring wells. The actual average capture zone width was estimated to be between 45 and 69 feet. Total TCE mass discharge reduction was maintained through the duration of the performance monitoring period and exceeded 99.99% (%). Decreases in TCE concentrations were observed at all four downgradient monitoring wells within the treatment zone (ranging from 50 to 74% at day 436), and the first arrival of treated water was consistent with model predictions. The field demonstration confirmed the HRX Well technology is best suited for long-term mass discharge control, can be installed under active infrastructure, requires limited ongoing operation and maintenance, and has low life cycle energy and water requirements. 相似文献
11.
Controlled‐source electromagnetic monitoring of reservoir oil saturation using a novel borehole‐to‐surface configuration 
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下载免费PDF全文 To advance and optimize secondary and tertiary oil recovery techniques, it is essential to know the areal propagation and distribution of the injected fluids in the subsurface. We investigate the applicability of controlled‐source electromagnetic methods to monitor fluid movements in a German oilfield (Bockstedt, onshore Northwest Germany) as injected brines (highly saline formation water) have much lower electrical resistivity than the oil within the reservoir. The main focus of this study is on controlled‐source electromagnetic simulations to test the sensitivity of various source–receiver configurations. The background model for the simulations is based on two‐dimensional inversion of magnetotelluric data gathered across the oil field and calibrated with resistivity logs. Three‐dimensional modelling results suggest that controlled‐source electromagnetic methods are sensitive to resistivity changes at reservoir depths, but the effect is difficult to resolve with surface measurements only. Resolution increases significantly if sensors or transmitters can be placed in observation wells closer to the reservoir. In particular, observation of the vertical electric field component in shallow boreholes and/or use of source configurations consisting of combinations of vertical and horizontal dipoles are promising. Preliminary results from a borehole‐to‐surface controlled‐source electromagnetic field survey carried out in spring 2014 are in good agreement with the modelling studies. 相似文献
12.
P.B. Wilkinson P.I. Meldrum O. Kuras J.E. Chambers S.J. Holyoake R.D. Ogilvy 《Journal of Applied Geophysics》2010,70(4):268-276
A permanent geoelectrical subsurface imaging system has been installed at a contaminated land site to monitor changes in groundwater quality after the completion of a remediation programme. Since the resistivities of earth materials are sensitive to the presence of contaminants and their break-down products, 4-dimensional resistivity imaging can act as a surrogate monitoring technology for tracking and visualising changes in contaminant concentrations at much higher spatial and temporal resolution than manual intrusive investigations. The test site, a municipal car park built on a former gasworks, had been polluted by a range of polycyclic aromatic hydrocarbons and dissolved phase contaminants. It was designated statutory contaminated land under Part IIA of the UK Environmental Protection Act due to the risk of polluting an underlying minor aquifer. Resistivity monitoring zones were established on the boundaries of the site by installing vertical electrode arrays in purpose-drilled boreholes. After a year of monitoring data had been collected, a tracer test was performed to investigate groundwater flow velocity and to demonstrate rapid volumetric monitoring of natural attenuation processes. A saline tracer was injected into the confined aquifer, and its motion and evolution were visualised directly in high-resolution tomographic images in near real-time. Breakthrough curves were calculated from independent resistivity measurements, and the estimated seepage velocities from the monitoring images and the breakthrough curves were found to be in good agreement with each other and with estimates based on the piezometric gradient and assumed material parameters. 相似文献
13.
14.
D. VOGELSANG 《Geophysical Prospecting》1987,35(5):604-617
Electromagnetic (EM) surveys using the horizontal coplanar loop (‘Slingram’) geometry have been successful in the location of karst aquifer systems in limestone areas of Germany and the Mediterranean. In spite of the rapid changes in shape and resistivity of karst pipes, correlations of significant EM minima can be made by reference to the main structural directions. The EM results have often been verified by drilling. EM prospecting need not be confined to limestone areas. It can be used on all hard rocks where faulting has created vertical zones with a resistivity contrast to the undisturbed rock. EM siting of wells has proved successful in water-supply schemes for several places. This method is now being applied as a routine, fast and low-cost procedure to tap ground-water resources in hard-rock areas. 相似文献
15.
The results of Zayü-Qingshuihe MT sounding profile carried out in eastern Tibetan Plateau are presented in this paper. Using 2-D RRI method, the resistivity distribution with depth is obtained along the profile. It is featured by the resistivity zones in the horizontal direction and layers in the vertical direction. The Bangong-Nujiang suture zone and Jinshajiang suture zone are both important electrical conductivity-separating zones in the plateau, and the former is a zone with relatively low resistivity while the latter is an electrical conductivity gradient zone. The highly electrical conductive bodies in the mid and lower crust of northern Qiangtang and Bayan Har Terrain might be caused by regional melting due to shear heating during the process of subduction in tectonic evolution. 相似文献
16.
Fluid injection monitoring using electrical resistivity tomography — five years of injection at Ketzin,Germany 下载免费PDF全文
下载免费PDF全文 P. Bergmann C. Schmidt‐Hattenberger T. Labitzke F.M. Wagner A. Just C. Flechsig D. Rippe 《Geophysical Prospecting》2017,65(3):859-875
Between the years 2008 and 2013, approximately 67 kilotons of CO2 have been injected at the Ketzin site, Germany. As part of the geophysical monitoring programme, time‐lapse electrical resistivity tomography has been applied using crosshole and surface‐downhole measurements of electrical resistivity tomography. The data collection of electrical resistivity tomography is partly based on electrodes that are permanently installed in three wells at the site (one injection well and two observation wells). Both types of ERT measurements consistently show the build‐up of a CO2‐related resistivity signature near the injection point. Based on the imaged resistivity changes and a petrophysical model, CO2 saturation levels are estimated. These CO2 saturations are interpreted in conjunction with CO2 saturations inferred from neutron‐gamma loggings. Apart from the CO2–brine substitution response in the observed resistivity changes, significant imprints from the dynamic behaviour of the CO2 in the reservoir are observed. 相似文献
17.
Pressure pulsing technology is an innovative method that has been developed with the aim of overcoming preferred flow paths associated with remediation techniques that rely on the injection of reagents. Numerical and field experiments were conducted to assess how pressure pulsing affects groundwater flow and solute transport during reagent injection. A series of field experiments were performed at two field sites where a monitoring network designed to capture the breakthrough of solutes delivered from an injection well was installed. Pressure pulsing and conventional injection methods were used at each site. One site was comprised of fine sand with low heterogeneity, while the other was moderately heterogeneous with discrete layers varying from fine sand to silt. The data suggest that breakthrough was more uniform for the pressure pulsing injections; however, this difference was minor and complicated by sorption of some of the tracers employed. The groundwater flow and solute transport modeling exercise simulated the rapid boundary pressure modulation that occurs in association with pressure pulsing. Two‐dimensional (2D) simulations revealed that repeated sudden onset of injection cessation produces brief periods of gradient reversal and the development of a mixing zone near the injection well. The spatial extents of this mixing zone were found to be highly dependent upon the hydraulic diffusivity of the medium, with medium heterogeneity and pulsing frequency playing secondary roles. Three‐dimensional (3D) numerical simulations were used to benchmark the observations from one of the field sites. The results from the modeling effort showed that solute breakthrough from a pressure pulsing injection is more dispersed relative to a conventional injection as a result of the mixing zone phenomenon; however, we were unable to directly observe this mixing zone using the instrumentation deployed at the two field sites. 相似文献
18.
为了提高随钻电磁波测井仪器的抗震能力,仪器传感器中所有发射与接收线圈均安装在柱状金属钻铤上的环状刻槽中,同时槽中充填高磁导率的铁氧体,以提高发射和接收效率.本文针对多环状刻槽钻铤中发射与接收线圈分布,研究建立一套随钻电磁响应的混合模拟算法.首先,根据环状刻槽几何尺寸以及轴向边界,将整个钻铤与外部的井眼和地层划分成多个不同电导率和磁导率分布的轴对称非均质各向同性层状模型,并应用混合法建立层状非均质地层中电磁场的半解析解与各个线圈上感应电动势的计算方法.其次,利用摄动原理给出随钻电磁测井中振幅比与相位差的空间灵敏度计算公式.然后,通过数值结果考察铁氧体磁导率和地层电导率变化对发射线圈的发射功率和接收线圈上感应电动势的影响,并确定各个接收线圈上感应电动势的动态变化范围,为仪器设计过程中选择合适的铁氧体提供理论依据.最后,通过空间灵敏度分布特征考察振幅比与相位差在探测特征上的差异. 相似文献
19.
孔隙结构对储层电性及测井解释评价的影响（英文） 总被引：1，自引：1，他引：0
在多个区块的测井评价工作发现,孔隙结构直接影响储集层的品质和油气层的电阻率,是测井准确评价流体性质的关键。岩石物理资料表明不同区块内影响储层孔隙结构的因素不同,但效果是一致的,即孔隙结构的复杂程度控制着储层的储集能力和渗透能力。孔隙结构的复杂程度影响了储层中导电流体的分布和含量,从而控制了储层的电阻率。储层出现低阻油气层的内因均为复杂的孔隙结构（骨架导电及工程原因除外）。测井储层评价在分析控制储层孔隙结构复杂程度的地质因素及储层分类的基础上,针对不同类型储层采用不同的模型、参数和标准,可以有效的认识储层品质和识别不同类型储层的流体性质。 相似文献
20.
Liang-Jun Yan Xiao-Xiong Chen Hao Tang Xing-Bing Xie Lei Zhou Wen-Bao Hu Zhong-Xin Wang 《应用地球物理》2018,15(1):26-34
Monitoring and delineating the spatial distribution of shale fracturing is fundamentally important to shale gas production. Standard monitoring methods, such as time-lapse seismic, cross-well seismic and micro-seismic methods, are expensive, timeconsuming, and do not show the changes in the formation with time. The resistivities of hydraulic fracturing fluid and reservoir rocks were measured. The results suggest that the injection fluid and consequently the injected reservoir are characterized by very low resistivity and high chargeability. This allows using of the controlled-source electromagnetic method (CSEM) to monitor shale gas hydraulic fracturing. Based on the geoelectrical model which was proposed according to the well-log and seismic data in the test area the change rule of the reacted electrical field was studied to account for the change of shale resistivity, and then the normalized residual resistivity method for time lapse processing was given. The time-domain electromagnetic method (TDEM) was used to continuously monitor the shale gas fracturing at the Fulin shale gas field in southern China. A high-power transmitter and multi-channel transient electromagnetic receiver array were adopted. 9 h time series of Ex component of 224 sites which were laid out on the surface and over three fracturing stages of a horizontal well at 2800 m depth was recorded. After data processing and calculation of the normalized resistivity residuals, the changes in the Ex signal were determined and a dynamic 3D image of the change in resistivity was constructed. This allows modeling the spatial distribution of the fracturing fluid. The model results suggest that TDEM is promising for monitoring hydraulic fracturing of shale. 相似文献