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91.
煤田中在煤层附近有煤层气砂岩储层、泥质砂岩储层的存在,声波、密度两种孔隙度测井是进行孔隙度探测的有效方法。但是,当煤层气砂岩储层、泥质砂岩储层含气饱和度较小时,其分辨能力较低,这时就可以利用三测向电阻率,通过阿尔奇公式来计算孔隙饱和度;或是统计计算区内煤层气储层下限值的方法,还可采用孔隙度挖补法,提高识别能力。 相似文献
92.
根据电测井所得数值,通过造浆水影响改正及颗粒度影响改正后,利用相关图判定地层水矿化度,达到半定量或接近定量分析水平,完成淡水勘探中只对淡水层进行评价,进而实现无岩心钻进,结合抽水试验结果,优化取水位置,获取水质好、涌水量大的效果。 相似文献
93.
通常不同岩性的声波速度不同,同一岩性因裂隙发育和风化程度不同,声波速度也不相同。声波测井技术就是依据岩层的这一特性,划分不同岩层及岩层的风化破碎程度。这里对某铁路线的勘测的声波测井结果进行统计分析,给出了测区钻孔揭露的主要岩石较完整状态的声波波速统计值和异常发育概率统计。 相似文献
94.
介绍了石油测井深度光电编码器测量系统的测量原理、系统组成以及电路分析,同时在对系统误差分析的基础上给出了具体校正方法。 相似文献
95.
Direct observations or deduced analysis indicate clearly that formation of intense fluxes of relativistic electrons is an important ingredient in the evolution of numerous active magnetized plasma systems. Examples of relativistic electron energization include the recovery phase of a planetary magnetic storm, post solar flare coronal activity and the afterglow of gamma ray bursts. It is suggested that there exists a universal mechanism, which may explain electron energization at the vastly different magnetized plasma environments. The favorite configuration consists of an inhomogeneous magnetic field anchored at a given magnetic structure and excitation of whistler waves due to external injection of low-energy non-isotropic electrons. The energization proceeds as a bootstrap process due to interaction with the propagating whistler waves along the inhomogeneous magnetic field. 相似文献
96.
A consistent approach to the frequency analysis of hydrologic data in arid and semiarid regions, i.e. the data series containing several zero values (e.g. monthly precipitation in dry seasons, annual peak flow discharges, etc.), requires using discontinuous probability distribution functions. Such an approach has received relatively limited attention. Along the lines of physically based models, the extensions of the Muskingum‐based models to three parameter forms are considered. Using 44 peak flow series from the USGS data bank, the fitting ability of four three‐parameter models was investigated: (1) the Dirac delta combined with Gamma distribution; (2) the Dirac delta combined with two‐parameter generalized Pareto distribution; (3) the Dirac delta combined with two‐parameter Weibull (DWe) distribution; (4) the kinematic diffusion with one additional parameter that controls the probability of the zero event (KD3). The goodness of fit of the models was assessed and compared both by evaluation of discrepancies between the results of both estimation methods (i.e. the method of moments (MOM) and the maximum likelihood method (MLM)) and using the log of likelihood function as a criterion. In most cases, the DWe distribution with MLM‐estimated parameters showed the best fit of all the three‐parameter models. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
97.
O. Reimer P. F. Michelson R. A. Cameron S. W. Digel D. J. Thompson K. S. Wood 《Astrophysics and Space Science》2007,309(1-4):523-526
Gamma-ray astrophysics depends in many ways on multiwavelength studies. The Gamma-ray Large Area Space Telescope (GLAST) Large
Area Telescope (LAT) Collaboration has started multiwavelength planning well before the scheduled 2007 launch of the observatory.
Some of the high-priority multiwavelength needs include: (1) availability of contemporaneous radio and X-ray timing of pulsars;
(2) expansion of blazar catalogs, including redshift measurements; (3) improved observations of molecular clouds, especially
at high galactic latitudes; (4) simultaneous broad-band blazar monitoring; (5) characterization of gamma-ray transients, including
gamma ray bursts; (6) radio, optical, X-ray and TeV counterpart searches for reliable and effective sources identification
and characterization. Several of these activities are needed to be in place before launch.
相似文献
98.
Kuster-Toksöz and Biot-Gassmann models for estimating velocities of longitudinal and shear waves on the basis of well-logging data were analysed. P-wave and S-wave velocity models are crucial for interpretation of seismic data. Discussed models enable determination with quite good accuracy, in some cases higher than the acoustic full wavetrains interpretation. Because velocity strongly depends on lithology and saturation of pore space, the selection of parameters of rock matrix, hydrocarbons and formation waters has a strong effect on the quality of velocities estimation. 相似文献
99.
基于地震相分析的孔隙度预测 总被引:1,自引:0,他引:1
这里主要讨论在地震相分析下的孔隙度预测。其基本原理是:首先对研究区块进行前期常规解释(合成记录、层位追踪、构造及断层解释),在此基础上利用地震相分析技术,并结合测井及岩芯资料对研究区进行沉积相带划分,将地震信息转化为地质信息;然后根据相带划分结果,对单一相带中的密度、声波速度与孔隙度井资料进行统计,拟合获得相关最好的波阻抗与孔隙度关系公式,这样多个相带就有不同的孔隙度计算公式;最后通过反演得到的波阻抗计算获得孔隙度。由于在横向上加入了地质解释,所以通过这种方法能够有效结合地质规律,提高三维孔隙度预测精度,还能更好地进行孔隙流体预测及储层评价。 相似文献
100.