共查询到20条相似文献，搜索用时 109 毫秒
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李哲新 《水文地质工程地质》1992,19(4):57-59
涌砂是影响水井寿命和水质的重要原因,一般成井工艺中多采用缠丝滤水管,有些由于井深,或井孔偏斜,排浆不彻底等造成填砾不当,致使井中涌砂,影响水质以致报废。为探索修复涌砂井,满城钻井队和一些单位,利用贴砾滤水管成井不需填砾料这一特点,进行了修复涌砂井的尝试,取得良好效果。 相似文献
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利用高新研制的新型贴砾滤水管具有较高的强度和特点，它可广泛应用于水井工程和旧井处理工程中，不仅能提高生产效率，降低成本，而且不彻底治理涌砂问题。 相似文献
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赵玉杰 《水文地质工程地质》1986,(3)
贴砾滤水管是一种新型水井过滤器,系地矿部探矿工程推广新项目,它是用合成树脂将一定粒径的砾石粘到衬管上制成的。它具有透水性能好,滤砂可靠,能够降低成井成本,使用方便等优点而受到广泛重视。目前西 相似文献
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张育芗 《水文地质工程地质》1980,(4)
SBFKK型滤水管用塑料管作内壁管,其内径为40—400毫米,最大可达800毫米,璧外带有贴砾层,贴砾厚度为11—18毫米,其规格如图1和表1所示。 贴砾层用净、洁圆形石英砾石 相似文献
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贴砾滤水管是一种新型水井过滤器。它是用合成树脂将一定粒度的砾石粘到钢制衬管上制成的。因其具有透水性能好,滤砂可靠,成井成本低,使用方便等优点而受到广泛重视。一些国家10年前已大量用于水井建造工程。我国于1978年在地矿部的支持关怀下,首先由天津地质局开始研制,在此期间他们对贴砾管的性能和制造工艺做了大量的室内研究、实验和测试工作,并 相似文献
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贴砾滤水管(简称贴砾管是近年研制成的一种新型滤水管。是以钢管做衬管,用合成树脂将一定粒径的石英砂粘到打眼衬管上制成的。具有良好的透水性和可靠的滤砂性。适用于粗砂、中砂、细砂、粉砂等含水地层,较好的解决了粉、细砂地层成井涌砂问题和深孔填砾不均匀、不准确甚至壅塞架桥等技术难 相似文献
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Andreas S. Stordal Hans A. Karlsen Geir Nævdal Hans J. Skaug Brice Vallès 《Computational Geosciences》2011,15(2):293-305
The nonlinear filtering problem occurs in many scientific areas. Sequential Monte Carlo solutions with the correct asymptotic
behavior such as particle filters exist, but they are computationally too expensive when working with high-dimensional systems.
The ensemble Kalman filter (EnKF) is a more robust method that has shown promising results with a small sample size, but the
samples are not guaranteed to come from the true posterior distribution. By approximating the model error with a Gaussian
distribution, one may represent the posterior distribution as a sum of Gaussian kernels. The resulting Gaussian mixture filter
has the advantage of both a local Kalman type correction and the weighting/resampling step of a particle filter. The Gaussian
mixture approximation relies on a bandwidth parameter which often has to be kept quite large in order to avoid a weight collapse
in high dimensions. As a result, the Kalman correction is too large to capture highly non-Gaussian posterior distributions.
In this paper, we have extended the Gaussian mixture filter (Hoteit et al., Mon Weather Rev 136:317–334, 2008) and also made the connection to particle filters more transparent. In particular, we introduce a tuning parameter for the
importance weights. In the last part of the paper, we have performed a simulation experiment with the Lorenz40 model where
our method has been compared to the EnKF and a full implementation of a particle filter. The results clearly indicate that
the new method has advantages compared to the standard EnKF. 相似文献
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Preparation of filter aids based on diatomites 总被引：1，自引：1，他引：1
Sanja Martinovic Milica Vlahovic Tamara Boljanac Ljubica Pavlovic 《International Journal of Mineral Processing》2006,80(2-4):255-260
Two major deposits of diatomaceous earth (diatomite) in the region of the Balkan Peninsula, the Kolubara basin (Serbia and Montenegro) and the Vesje deposit (Former Yugoslav Republic of Macedonia), were selected for detailed investigation of their possible application in preparation of beer filter aids. Chemical, mineralogical and structural properties of diatomite samples were analyzed with the aim of predicting the filtration efficiency. Results of beer filtering compounds preparation are presented in this paper. The parameters of crushing, drying, calcination and classification are also defined. Beer filtration tests proved diatomites to be satisfactory and not causing any degradation of filtration process or beer quality. Technological flow scheme for obtaining the beer filter aids is proposed in the paper. 相似文献
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James R. Carr 《Mathematical Geology》1990,22(8):1063-1079
Data-processing requirements for remotely sensed, digital images include spatial filtering to suppress image noise, enhance edges/contacts, and improve image clarity. Spatial filter theory demonstrates that the addition of a high-pass filtered image to a low-pass filtered image yields the original digital image. Application of this principle in kriging can be accomplished by using the same covariance matrix to solve for two weighting vectors to yield a result analogous to low- and high-pass filtering. The addition of kriged estimates calculated using both weighting vectors is analogous to summing high-, and low-pass filtered digital images. This modified method of kriging yields estimates associated with less smoothing compared to ordinary kriging. Statistical moments of original sample data are better preserved through estimation by this method. 相似文献
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Andreas S. Stordal Randi Valestrand Hans Arnfinn Karlsen Geir N?vdal Hans Julius Skaug 《Computational Geosciences》2012,16(2):467-482
Over the last years, the ensemble Kalman filter (EnKF) has become a very popular tool for history matching petroleum reservoirs.
EnKF is an alternative to more traditional history matching techniques as it is computationally fast and easy to implement.
Instead of seeking one best model estimate, EnKF is a Monte Carlo method that represents the solution with an ensemble of
state vectors. Lately, several ensemble-based methods have been proposed to improve upon the solution produced by EnKF. In
this paper, we compare EnKF with one of the most recently proposed methods, the adaptive Gaussian mixture filter (AGM), on
a 2D synthetic reservoir and the Punq-S3 test case. AGM was introduced to loosen up the requirement of a Gaussian prior distribution
as implicitly formulated in EnKF. By combining ideas from particle filters with EnKF, AGM extends the low-rank kernel particle
Kalman filter. The simulation study shows that while both methods match the historical data well, AGM is better at preserving
the geostatistics of the prior distribution. Further, AGM also produces estimated fields that have a higher empirical correlation
with the reference field than the corresponding fields obtained with EnKF. 相似文献
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渗透性曲线是反映非饱和土中水分运移的重要参数，瞬态剖面法是测定渗透性曲线的常用方法。将滤纸法应用于传统的瞬态剖面法，设计了一种土柱装置，用于测定土体的渗透性曲线。该装置包括上部能够持续给水的供水系统及下部由带环刀的土样与滤纸叠置而成的土柱。在水分下渗过程中，定期测量土样与滤纸的质量以获得土柱的含水率剖面与水头剖面，根据所测数据计算得到土?水特征曲线和渗透性曲线。用此方法测得甘肃正宁马兰黄土与第1层古土壤的渗透性曲线和土?水特征曲线，该方法测量的吸力范围大，为1～105 kPa，渗透系数范围在10?5～10?13 m/s。用常见的统计预测模型预测了土体的渗透性曲线，并与实测曲线对比发现小吸力范围预测值与实测值相符，大吸力范围预测值偏差较大。 相似文献
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M. Maccarini 《Geotechnical and Geological Engineering》1993,11(4):263-268
Summary This note deals with the mechanical behaviour of lateral filter paper drains, used in triaxial testing in the laboratory. It has been found that the maximum influence of the filter paper drain on the measured deviator stress coincides with the development of folds during axial straining. Subsequent reuse of the same filter paper drain caused a significant drop of about 70% in the maximum value of the influence. 相似文献