钻孔孔径的变化对γ测井解释含量的影响     

周明海 《铀矿地质》1989,5(2):102-107

钻孔孔径变化与矿床类型、钻进孔径、矿化岩性、矿层品位、矿层厚度、冲冼液的性质以及工程切穿矿层的时间有着密切的关系。孔径变化对γ测井解释含量、矿床储量的增减影响甚大。理论和实践证明,专门性的孔径测量,是提高γ测井质量、准确确定矿层品级的重要措施之一,对提高矿床经济效益也具有重要意义。  相似文献   

A ‘mathematical’ spider living on gravel plains of the Namib Desert     

G. Costa  A. Petralia  E. Conti  C. Hnel 《Journal of Arid Environments》1995,29(4)

In certain areas of the Namib gravel plains a new Ariadna sp. was discovered. It rims its vertical burrow with a stone circle, made on average of seven quartz stones. Some mathematical relationships between hole diameter, stone sizes and weight, and animal size were studied. A correlation was found, and stone selection by this spider postulated. Different hypotheses on the adaptive value of stone circle are suggested.  相似文献   

浅析云峰井变径前后气压效应与井径比的关系     

刘亚辉 《东北地震研究》1993,(4)

本文通过改变云峰井孔径试验,探讨了提高地下水观测井映震能力的一种途径。  相似文献   

Observations of geomagnetic pulsations and variations with a new borehole magnetometer down to depths of 3000 m   总被引：1，自引：0，他引：1  

K. Spitzer 《Geophysical Journal International》1993,115(3):839-848

b
A triaxial magnetometer has been developed for investigating the in situ skin effect of horizontal geomagnetic pulsations and variations in deep boreholes. The observations were carried out in the pilot borehole of the Continental Deep Drilling Program of Germany (KTB) down to depths of 3000 m and up to temperature of 90 C. A weak skin effect, due to the known very low conductivity of the penetrated crystalline rocks, of 90 to 95 per cent in amplitude and -5 to -10 rotation in phase has been observed at periods of 10 s and magnetometer depth of 2400 m.
An essential prerequisite for all calculations is the accurate determination of the orientation of the downhole magnetometer. It is demonstrated how oriented record samples of temporal variations at depth correlate precisely with those from the surface.
Results from surface magnetotelluric (MT) investigations show strong local distortions of the telluric field. The distortion of the MT tensor response has been determined by means of newly introduced skin-effect transfer functions, which are assumed to be undistorted.  相似文献   

钻孔伽玛场理论及形态系数计算的进一步研究     

段波 《铀矿地质》1991,7(1):49-58

  相似文献   

苏北平原井下摆观测效果的讨论     

徐元耀 《地震地磁观测与研究》1994,15(6):31-35

文章以江苏省大丰台、盐城台、淮阴台、海安台，射阳台井下摆观测为例。比较它们的观测结果，分析认为井下摆的观测效果不仅与地面复盖层的厚度有关，而且与井下摆周围的环境干扰，观测用井的质量有关。为了提高井下摆观测效果，应尽量减少环境干扰，并注意井的垂直度和固井，文章还指出，沿海地区井下摆受海浪干扰相当显著的。  相似文献   

Borehole pressure correction equation     

R. R. Britton  J. S. Gozon 《Geotechnical and Geological Engineering》1986,4(1):67-71

Conclusion A method of calculation for borehole pressure has been developed and compared to measured data for PETN. The results show that by adjusting the ratio of the specific heats using an equation derived from a curve fit of a pressure as a function of decoupling ratio graph, the plot shifts to a position within the ranges of the measured data. Also, at this point the proper specific heat may be obtained for a given gaseous mixture. Although other mixtures have been considered the results are not yet conclusive, but preliminary values seem to hold for the methodology used.  相似文献   

Investigation of electrical anisotropy in the deep borehole KTB     

Armin Rauen  Marcela Lastovickova 《Surveys in Geophysics》1995,16(1):37-46

Information about electrical anisotropy in and around the deep borehole of the German Continental Deep Drilling Program (KTB) has been acquired using three different methods: (1) Under surface temperature and pressure conditions, the azimuthal dependence of resistivity has been measured in horizontal planes perpendicular to the axes of drill cores. (2) Simulated in-situ conditions (high temperature and pressure) have been applied to mini cores drilled at different orientations to structural features such as foliation. The resistivity was then measured in the direction of the mini cores' long axes. (3) Under quasi-in-situ (downhole) conditions, the azimuthal dependence of resistivity has been measured in horizontal planes using the Azimuthal Resistivity Imager (ARI), a down hole logging tool.These investigations have shown that electrical anisotropy is strongly related to structural features. The anisotropy of gneisses is the highest due to the strong foliation (averaged anisotropy factor 2.8). Lamprophyres are most isotropic (factor 1.2). Most rocks from KTB are amphibolites with intermediate anisotropies (factor 1.3). The anisotropies measured under surface temperature and pressure conditions and quasi-in-situ conditions on amphibolites are approximately the same, whereas anisotropies under simulated in-situ conditions are partially higher.Furthermore, the anisotropies measured on the cm to m scale using the various methods outlined above shall be compared with large scale anisotropies of the km scale measured around KTB using Magneto Tellurics.  相似文献   

长螺旋钻孔泵压灌注CFG桩缩径与对策   总被引：1，自引：0，他引：1  

贺为民  尚红  孙铭心  刘明军  常河林 《水文地质工程地质》2002,29(2):62-63,65

CFG桩是水泥粉煤灰碎石桩的简称。长螺旋钻孔泵压灌注CFG桩在层状土层的软硬分界处及软土中出现缩径，通过降低提钻速率和设置降水井点，缩径问题有所缓解，采取复打技术后彻底解决了缩径问题。  相似文献   

北京昌平地震台TJ-1体积钻孔应变仪潮汐参数动态特征及其稳定性研究     

唐九安  王勇  刘福生 《华北地震科学》2001,19(4):34-40

介绍了北京昌平地震台 TJ- 1型钻孔体积应变仪 1 989年 7月～ 2 0 0 0年 1 2月期间的观测结果 ,分析了潮汐响应函数的动态特征及其稳定性。由全序列观测数据调和分析所得 :O1波潮汐因子 VO1=0 .791 6± 0 .0 1 2 8、相位滞后 ΔΦ0 1=1 .9°;K1波潮汐因子 Vk1=0 .6 4 42±0 .0 0 88、相位滞后ΔΦk1=- 4.2°;M2 波潮汐因子 VM2 =0 .6 5 0 0± 0 .0 0 3 8、相位滞后ΔΦM2 =-2 .9°。液态地核振荡因子 A=VO1/VK1=1 .2 2 8,比理论值小 6 .5 %。  相似文献