储层岩石电性特征的逾渗网络模型研究(英文)     

王克文  孙建孟  关继腾  苏远大 《应用地球物理》2005,2(4):223-229

建立能够反映储层孔隙结构、流体特征的逾 渗网络模型,通过数值模拟研究了储层孔隙尺寸、 孔隙形状、连通性、微孔隙的发育状况等对I-Sw曲 线影响的定性规律,研究了地层水矿化度对岩石电 阻率的影响。分析讨论了不同因素对电阻率影响的 相对强度。最后,通过曲线拟合定量地研究了不同 因素对I-Sw曲线的影响规律。研究表明,在上述影 响因素中连通性和微孔隙对I-Sw曲线的影响很大, 其它因素的影响强度较小。地层水矿化度对岩石电 阻率绝对值的影响很大。“非阿尔奇”现象普遍存在, 在低渗透(低连通性)储层岩石中更为明显。  相似文献   

嘉山地震台地电阻率数字化改造     

赵桂宝 《地震地磁观测与研究》2005,(Z1)

地球科学是一门观测科学,地震观测是研究与应用的基础。地电阻率作为地震前兆观测手段之一,发挥着日益重要的作用,而良好的观测系统是产出连续、可靠、高质量数据的前提。因此,对观测系统的数字化改造工作必须予以高度重视。本文对嘉山台地电阻率数字化改造工作进行了简要介绍,并就一些技术问题进行了论述。  相似文献   

Two-dimensional inversion of direct current resistivity data using a parallel, multi-objective genetic algorithm   总被引：2，自引：0，他引：2  

Christoph Schwarzbach  Ralph-Uwe Börner  Klaus Spitzer 《Geophysical Journal International》2005,162(3):685-695

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Macropores as preferential flow paths in meander bends          下载免费PDF全文

Garrett T. Menichino  Adam S. Ward  Erich T. Hester 《水文研究》2014,28(3):482-495

Macropores are subsurface connected void spaces caused by processes such as fracture of soils, micro‐erosion, and fauna burrows. They are common near streams (e.g. hyporheic and riparian zones) and may act as preferential flow paths between surface and groundwaters, affecting hydrologic and biogeochemical processes. We tested the hydrologic function of macropores by constructing an artificial macropore within the saturated zone of a meander bend (open macropore, ‘OM’) and later filling its upstream end (partially filled macropore, ‘PFM’). For each treatment, we injected saline tracer at an upgradient monitoring well within the meander and monitored downgradient hydraulics and tracer transport. Pressure transducers in monitoring wells indicated hydraulic gradients within the meander were 32% higher perpendicular to and 6% higher parallel to the macropore for the OM than for the PFM. Additionally, hydraulic conductivities measured via falling head tests were 29 to 550 times higher along the macropore than in nearby sediment. We used electrical conductivity probes in wells and electrical resistivity imaging to track solute transport. Transport velocities through the meander were on average 9 and 21% higher (per temporal moment analysis and observed tracer peak, respectively) for the OM than for the PFM. Furthermore, temporal moments of tracer breakthrough analysis indicated downgradient longitudinal dispersion and breakthrough tracer curve tailing were on average 234% and 182% higher for the OM, respectively. This suggests the OM enabled solute transport at overall shorter timescales than the matrix but also increased tailing. Our results demonstrate the importance of macropores to meander bend hydrology and solute transport. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

Ressi experimental catchment: Ecohydrological research in the Italian pre-Alps     

Giulia Zuecco  Chiara Marchina  Ylenia Gelmini  Anam Amin  H. J. van Meerveld  Daniele Penna  Marco Borga 《水文研究》2021,35(3):e14095

Ressi is a small (2.4 ha) forested catchment located in the Italian pre-Alps. The site became an experimental catchment to investigate the water fluxes in the soil–plant–atmosphere continuum and the impact of vegetation on runoff generation in 2012. The elevation of the catchment ranges from 598 to 721 m a.s.l. and the climate is humid temperate. The bedrock consists of rhyolites and dacites; the soil is a Cambisol. The catchment is covered by a dense forest, dominated by beech, chestnut, maple, and hazel trees. The field set up includes measurements of the rainfall in an open area, streamflow at the outlet, soil moisture at various depths and locations, and depth to water table in six piezometers at a 5- or 10-min interval. Samples of precipitation, stream water, shallow groundwater and soil water are collected monthly for tracer analysis (stable isotopes (²H and ¹⁸O), electrical conductivity and major ions), and during selected rainfall–runoff events to determine the contribution of the various sources to runoff. Since 2017, soil and plant water samples have been collected to determine the sources of tree transpiration. Data collected in the period 2012–2016 are publicly available. Data collection is ongoing, and the data set is expected to be updated on an annual basis to include the most recent measurements.  相似文献   

A long‐term study of stable isotopes as tracers of processes governing water flow and quality in a lowland river basin: the upper Thames,UK          下载免费PDF全文

W. George Darling  Michael J. Bowes 《水文研究》2016,30(13):2178-2195

A long‐term study of O, H and C stable isotopes has been undertaken on river waters across the 7000‐km² upper Thames lowland river basin in the southern UK. During the period, flow conditions ranged from drought to flood. A 10‐year monthly record (2003–2012) of the main River Thames showed a maximum variation of 3‰ (δ¹⁸O) and 20‰ (δ²H), although interannual average values varied little around a mean of –6.5‰ (δ¹⁸O) and –44‰ (δ²H). A δ²H/δ¹⁸O slope of 5.3 suggested a degree of evaporative enrichment, consistent with derivation from local rainfall with a weighted mean of –7.2‰ (δ¹⁸O) and –48‰ (δ²H) for the period. A tendency towards isotopic depletion of the river with increasing flow rate was noted, but at very high flows (>100 m³/s), a reversion to the mean was interpreted as the displacement of bank storage by rising groundwater levels (corroborated by measurements of specific electrical conductivity). A shorter quarterly study (October 2011–April 2013) of isotope variations in 15 tributaries with varying geology revealed different responses to evaporation, with a well‐correlated inverse relationship between Δ¹⁸O and baseflow index for most of the rivers. A comparison with aquifer waters in the basin showed that even at low flow, rivers rarely consist solely of isotopically unmodified groundwater. Long‐term monitoring (2003–2007) of carbon stable isotopes in dissolved inorganic carbon (DIC) in the Thames revealed a complex interplay between respiration, photosynthesis and evasion, but with a mean interannual δ¹³C‐DIC value of –14.8 ± 0.5‰, exchange with atmospheric carbon could be ruled out. Quarterly monitoring of the tributaries (October 2011–April 2013) indicated that in addition to the aforementioned factors, river flow variations and catchment characteristics were likely to affect δ¹³C‐DIC. Comparison with basin groundwaters of different alkalinity and δ¹³C‐DIC values showed that the origin of river baseflow is usually obscured. The findings show that long‐term monitoring of environmental tracers can help to improve the understanding of how lowland river catchments function. Copyright © NERC 2015. Hydrological Processes © 2015 John Wiley & Sons, Ltd.  相似文献   

GEOPHYSICAL EXPLORATION     

《Abstract of Chinese Geological Literature》2014,(2)

正20141074Bao Xijie(Research Institute of Exploration and Development,Daqing Oilfield Company,PetroChina,Daqing 163712,China)Gather Optimal Processing and Application Effect of Prestack AVA Instantaneous Inversion  相似文献   

荒漠绿洲湿地土壤水热盐动态过程及其影响机制     

孟阳阳  刘冰  刘婵 《中国沙漠》2019,39(1):149-160

以甘肃临泽荒漠绿洲湿地为研究对象，通过对土壤温度、含水量、电导率及蒸散量的野外观测，在植物生长期和冻融期分别深入分析水热盐耦合运移过程及其影响因素，探讨水热梯度对盐分运移及其分布格局的控制作用。结果表明：土壤温度整体呈现出春夏季逐渐升高、秋冬季降低趋势。在冻结期，土壤表现为脱盐状态，表层电导率由2.8 mS·cm^-1降到1.2 mS·cm^-1；而在消融期为积盐状态，表层电导率由1.2 mS·cm^-1升到3.7 mS·cm^-1。在生长期，土壤含水量和电导率波动较为剧烈，表层含水量27%~43%，表层电导率3~5.5 mS·cm^-1，土壤脱盐、积盐反复出现。全年蒸散量总体呈单峰变化趋势，年蒸散量507 mm；土壤电导率与蒸散量呈正比关系，与地下水位呈负相关关系；蒸散发作用是土壤表层积盐的主要驱动力，而地下水波动影响着湿地脱盐、洗盐过程。因此，荒漠绿洲湿地土壤盐分累积过程是水分运移和热量传输过程发生变化的结果。  相似文献   

四极法电阻率测量在石油管道防腐蚀中的应用     

许越 《地质与勘探》2016,52(3):551-555

土壤电阻率是地下石油管道一个重要的腐蚀性指标,因为管道的腐蚀程度和土壤电阻率的大小密切相关。本文介绍了四极法电阻率测量的原理和实施过程,并应用于某石油管道周围土壤的勘测,对测试数据做了处理和分析,为输油管道施工设计的防腐蚀提供了科学依据。  相似文献   

三维高密度电阻率法在堤坝工程中的模拟试验     

张汝凯  张晓培  吕守航  陈兵兵  王杰 《世界地质》2016,35(4):1133-1137

为检测堤坝中裂隙、洞穴及渗漏层等隐患的存在,利用三维高密度电阻率法对数字模型和物理模型建立的裂隙隐患进行探测,结果表明室内建立的物理模型在立体图和分层切片图中裂隙的形态有些变化,但其分布范围、位置与相对各自模型中实际的比例尺寸相差不大,说明数值模拟得出的结论可以为实际工程进行理论指导,具有一定的参考价值。  相似文献