储层条件下波速的变化规律及其影响因素的实验研究   总被引：18，自引：1，他引：17       下载免费PDF全文

施行觉  吴永钢 《地球物理学报》1998,41(2):234-241

为了在模拟储层的温度压力条件下,更精确地测定大庆砂岩样品在干燥、饱水和饱油等不同情况下的纵、横波速及其变化规律,首先对由于岩石的非完全弹性而引起的隐伏效应、滞后效应等因素对波速测量的影响进行了分析,提出了相应的改进方法以提高测试的精度．实验结果表明,波速随压力的增大以对数形式增加,随温度的升高呈线性减小．通过实测数据的分析和计算,提出了压力影响系数和温度影响系数,且认为它们与岩性参数有关．  相似文献   

多层球体对电磁场散射响应的求解方法   总被引：1，自引：1，他引：0       下载免费PDF全文

徐建华  聂在平 《地球物理学报》1998,41(6):865-876

为建立多层球体对电磁场散射响应的求解方法,将球外入射电磁场分为TM和TE极化波两部分,通过求解Debye位方程可得到多层球体各层中两种极化场的通解形式,利用边界条件建立了TM波（或TE波）球面波阻抗（或导纳）的递推关系,借助于阻抗（或寻纳）导出了球体对TM波（或TE波）所产生散射场的一般表达式．文中具体求解了球体对平面波径向和横向偶极子场的散射响应．  相似文献   

厦门市的震前电磁波观测     

叶清 《福建地震》1998,(3)

本文记述了厦门市地震局几年来开展电磁波观测的情况,以及对各种非震异常信号的识别探索。  相似文献   

Decompaction mechanism of deep crystalline rocks under stress relief     

F. F. Gorbatsevich   《Tectonophysics》2003,370(1-4):121-128

Within a geological massif in a stable geodynamical situation contacts on the grain boundaries in polycrystalline rocks at great depths are continuous and firm. The stress release of those rocks during drilling and excavation to the surface is accompanied by their disintegration (decompaction). The reason for the decompaction is generation of microcracks during stress release due to the difference between the elastic moduli of crystalline grains at their contacts. The mechanism of decompaction may occur not only in polymineral but in polycrystalline rocks as well. The method of decompaction evaluation of deep crystalline rocks under stress relief is presented. According to the calculations the initial manifestation of the decompaction effect in biotite gneisses will occur when they are extracted from the deep range of 0.8–1 km. The first microcracks arise on the grain borders between quartz–biotite and oligoclase–biotite. It is shown that the uplift of gneiss–granite varities of the rocks cut by the Kola superdeep borehole from depths exceeding 13–15 km will be possible in a form of separate mineral grains. Practical importance of the presented method is in an opportunity to evaluate the level of excavated decompaction. The method allow estimating the depth, from which the rock will be extracted only in a sludge form.  相似文献   

On arrangement of source and receivers in SASW testing   总被引：1，自引：0，他引：1  

Longzhu Chen  Jinying Zhu  Xishui Yan  Chunyu Song 《Soil Dynamics and Earthquake Engineering》2004,24(5):389-396

This study investigates the effects of source and receivers arrangement on the Rayleigh wave dispersion curve in SASW testing. Analytical studies and numerical simulations with coupled finite and infinite elements are presented in this paper. It is shown that arrangement of source and receivers has a significant effect on test results, especially for soils with high Poisson's ratio or saturated soils. Larger source-to-receiver distance and receiver spacing usually give better results, and it is unnecessary to keep them equal. To satisfy the error control requirement in Rayleigh wave phase velocity measurement, source-to-receiver distance and receiver spacing should meet corresponding minimum values, which are proposed for different Poisson's ratios of soil in this paper.  相似文献   

应用二维地震勘查恩洪盆地煤层气     

王朝栋  桂宝林  赵永学  杨德义  刘充  唐永洪 《云南地质》2004,23(4):509-514

在恩洪煤层气勘查中，为攻破难关，根据地质特点、诸多物探方法中，首选二维地震勘探，在煤层埋深大于300m以上的未经勘探区，进行区域性了解。查清区内地层发育情况，煤层埋藏深度、厚度及变化情况。了解区内断层及其性质，对主要煤层的展布进行追踪，经过勘探结果，在高原山区利用地震勘探取得了较好的地质效果。  相似文献   

Wave interaction with one or two rows of closely spaced rectangular cylinders   总被引：1，自引：0，他引：1  

Zhenhua Huang   《Ocean Engineering》2007,34(11-12):1584-1591

Experimental results are reported on the wave reflection from and transmission through one row or two rows of closely spaced rectangular cylinders. An empirical expression is proposed for the friction factor which models the head loss due to closely spaced rectangular cylinders. Algebraic expressions are presented to calculate the reflection and transmission coefficients of regular waves for a single slotted wall or double slotted walls. The model is validated by the published and present experimental results. The proposed method can be used for the preliminary design of slotted-wall breakwaters.  相似文献   

Forecasting and hindcasting waves with the SWAN model in the Southern California Bight     

W. Erick Rogers  James M. Kaihatu  Larry Hsu  Robert E. Jensen  James D. Dykes  K. Todd Holland 《Coastal Engineering》2007

The Naval Research Laboratory created a wave forecasting system in support of the Nearshore Canyon Experiment (NCEX) field program. The outer nest of this prediction system encompassed the Southern California Bight. This forecasting system is described in this paper, with analysis of results via comparison to the extensive buoy network in the region. There are a number of potential errors, two of which are poor resolution of islands in the Bight—which have a strong impact on nearshore wave climate—and the use of the stationary assumption for computations. These two problems have straightforward solutions, but the solutions are computationally expensive, so an operational user must carefully consider their cost. The authors study the impact of these two types of error (relative to other errors, such as error in boundary forcing) using several hindcasts performed after the completion of NCEX. It is found that, with buoy observations as ground truth, the stationary assumption leads to a modest increase in root-mean-square error; this is due to relatively poor prediction of the timing of swell arrivals and local sea growth/decay. The model results are found to be sensitive to the resolution of islands; however, coarse resolution does not incur an appreciable penalty in terms of error statistics computed via comparison to buoy observations, suggesting that other errors dominate. Inaccuracy in representation of the local atmospheric forcing likely has a significant impact on wave model error. Perhaps most importantly, the accuracy of directional distribution of wave energy at the open ocean boundaries appears to be a critical limitation on the accuracy of the model-data comparisons inside the Bight.  相似文献   

Numerical simulation of sediment lifted by waves and transported by tidal currents     

Cao Zude  Wang Guifen 《海洋学报(英文版)》1994,13(3):433-443

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近海遥测波浪仪的数据采集与处理     

廖康明  林雨良 《台湾海峡》1992,11(3):268-272

为了解决HBF1-1型近海遥测波浪仪的原始数据保留方式与数据处理能力,本文提出了以IBM/PC微机代替原系统单板机的方法,并设计了“ADL”与“SPE”数据采集与处理程序,经与ENDECO 956浮标观测资料的比较以及1a的海上观测应用,证明该方法所获得的资料是可靠的。  相似文献