静压法施工预应力混凝土管桩的质量管理

预应力混凝土管桩采用静压法施工越来越普遍,其施工质量问题也倍受关注,现对其质量管理问题作本文谈论。     

陡坡复杂扇体油藏评价思路与方法

本文以东营凹陷北部陡坡带为例论述了陆相断陷盆地陡坡复杂扇体油藏评价思路与方法。分析了陡坡带特殊性及复杂性,针对复杂扇体油藏精细等时地层对比、控砂机制、有效储层划分和油气分布的纵向分带性提出了有效的研究方法,并形成了一整套有针对性的勘探技术流程,在东营凹陷乃至济阳坳陷具有较好的推广前景。     

琼东南盆地深水区断层垂向输导及成藏模式

In the Qiongdongnan Basin, faults are well developed.Based on the drilling results, the traps controlled two or more faults are oil-rich. However, when only one fault cut through the sand body, there is no sign for hy-drocarbon accumulation in the sandstone. In terms of this phenomenon, the principle of reservoir-forming controlled by fault terrace is proposed, i.e., when the single fault activates, because of the incompressibility of pore water, the resistance of pore and the direction of buoyancy, it is impossible for hydrocarbon to ac-cumulate in sandstone. But when there are two or more faults, one of the faults acts as the spillway so the hydrocarbon could fill in the pore of sandstone through other faults. In total five gas bearing structures and four failure traps are considered, as examples to demonstrate our findings. According to this theory, it is well-advised that south steep slope zone of Baodao-Changchang Depression, south gentle slope zone of Lingshui Depression, north steep slope zone of Lingshui Depression, and north steep slope zone of Baodao Depression are the most favorable step-fault zones, which are the main exploration direction in next stage.     

天气预报分析型数据模型及生成

将原始数据转换为分析型数据,增强用户对海量数据的分析能力,是数据仓库技术最核心、最有价值的思想,也是数据仓库在气象领域应用的基础。该文针对天气预报领域数据空间性、瞬变性、物理性和多尺度性等特点,提出了五元组描述的天气预报分析型数据概念模型;总结了生成分析型数据的固定区域统计、划分区域统计、基本天气系统识别和天气学概念模型识别4种聚集变换,并对其关键技术进行了讨论。提出了基本天气系统自动识别的滤波-划分-测量算法,探讨了针对气象数据特点的模糊空间关系,定义了进行天气学概念模型识别的空间模糊产生式规则,并针对空间数据给出了定位条件等扩展。     

Thermal waters in the Lower Yarmouk Gorge and their relation to surrounding aquifers

Sources and mineralization of groundwaters from Cretaceous A7/B2 and B4 limestone aquifers in the Golan and Ajloun Heights are derived from conjoint discussion of stable isotopes of water and sulphate, major ion chemistry, rare earth distribution patterns and the (hydro)geological setting. Isotope fractionation of precipitation was used to derive elevation and continental influence of recharge areas. Positive shift of δ¹⁸O and δ²H occur due to evaporation before replenishment and the interaction with basalts. Major infiltration areas for Golan Heights are the limy foothills of the Mt. Hermon and for the Ajloun Heights the Plateau itself. To a less degree, precipitation infiltrates also the basaltic catchments. Groundwaters are mineralized by water/rock (i) variably altered limestones by diagenesis, (ii) evaporates and seawater brines enclosed in limestone matrix and (iii) locally occurring basaltic intrusiva. In the Yarmouk Gorge, a deep-seated brine of the Ha’on type ascends and mixes with the fresh shallow groundwater.Contrasting the macro chemical composition, REY distribution patterns indicate the lithology of the recharge areas. Infiltration over basalts results in REY patterns distinctly different to those derived from limy catchments.REY and isotope fingerprints prove that water from the Syrian Hauran Plateau is recharging springs and wells in the lowermost Yamouk gorge. The basaltic cover of the Golan Heights is of minor importance for recharge of the underlying A7/B2 aquifer, which becomes recharged at the foothills of Mt. Hermon and gets confined southwards. Even the wells in the basaltic cover receive water from the underlying limestone aquifer.Anomalous heat flux near the Yarmouk gorge and locally in the western escarpment of the Ajloun may be produced by ascending fluids from greater depth and/or by basaltic intrusions.     

干涸尾闾湖盆区泥漠地表磨蚀释尘特征

沙粒的表面磨蚀效应是地表产尘、释尘的重要机制,针对干湖盆泥漠地表开展磨蚀释尘实验研究,对理解干湖盆地表风蚀过程及盐碱尘暴形成机理具有重要意义。对采自西居延海干涸湖盆泥漠地表土样进行室内磨蚀模拟实验,研究了不同粒级（细、中、粗）沙粒不同落沙角度（30°,45°,60°）的磨蚀效应。结果表明：（1）泥漠地表磨蚀实验中能够产生明显释尘效应的沙粒粒级阈值为中沙（0.25 mm<M_d<0.50 mm）;（2）磨蚀粒径粒级相同时,磨蚀角度会对泥漠地表磨蚀释尘速率产生影响,磨蚀量的角度排序为60°>30°>45°,但同一粒级3种角度下的磨蚀释尘率差异不显著。（3）磨蚀角度为45°时,计算了泥漠地表的质量磨蚀率与能量磨蚀率,其中中沙为0.04 g·kg^-1、0.43 g·J^-1,粗沙为0.08 g·kg^-1、0.74 g·J^-1,极粗沙为0.26 g·kg^-1、2.54 g·J^-1;在磨蚀沙粒粒级倍增而磨蚀角度不变情况下,泥漠地表磨蚀释尘率与能量磨蚀率未发生正比例线性增长变化。     

神经网络辅助的GPS/MEMS-INS组合导航算法

在GPS/MEMS-INS(Micro-electromechanical System-Inertial Navigation System)组合导航中,当载体处于恶劣环境下或者载体处于大机动运动情况下,会导致GPS失锁。此时单独工作的低精度MEMS-INS会由于其位置和速度误差随着时间的变化而迅速积累最终无法导航。针对此问题,设计了一种结构简单易于实现的神经网络辅助的GPS/MEMS-INS组合导航系统。通过模拟实验,与标准卡尔曼滤波(KF)和无迹卡尔曼滤波(UKF)框架下组合导航相比,所提出的结构简单容易实现的神经网络辅助的组合导航系统具有较高的稳定性,并且组合导航整体过程中经纬度与速度精度均提高了65%左右。     

洛川黄土地层渗透性与孔隙性的关系

本文用逐步回归分析方法对洛川黄土孔隙性诸要素进行了变量筛选,选出了影响渗透系数的孔隙要素,并建立了随机数学模型,定量解决了影响渗透系数的孔隙多少和孔隙形状问题,初步确定出了洛川黄土地层透水性与孔隙性的关系。     

网袖扭转及其排除的模拟试验

网袖扭转是单拖渔轮用网囊引纲船舷一侧起网时有发生的现象。本模拟试验,可清楚地观察到网袖扭转的角度、方向,从而采取安全、简便快捷的方法排除。操作:面向船尾,右舷收网的顺时针方向扭转一周,左舷收网的逆时针方向扭转一周,排除时连接着网囊引纲一侧的网袖和混含纲保持不动,解开连接另一网袖叉纲一端的混合纲,顺其向绕另一混合纲一周并接回原处,网袖扭转便排除。     

Stability analysis of seabed strata and casing structure during the natural gas hydrates exploitation by depressurization in horizontal wells in South China Sea

Natural gas hydrates (NGHs) are a new type of clean energy with great development potential. However, it is urgent to achieve safe and economical NGHs development and utilization. This study established a physical model of the study area using the FLAC^3D software based on the key parameters of the NGHs production test area in the South China Sea, including the depressurization method, and mechanical parameters of strata, NGHs occurrence characteristics, and the technological characteristics of horizontal wells. Moreover, this study explored the law of influences of the NGHs dissociation range on the stability of the overburden strata and the casing structure of a horizontal well. The results are as follows. With the dissociation of NGHs, the overburden strata of the NGHs dissociation zone subsided and formed funnel-shaped zones and then gradually stabilized. However, the upper interface of the NGHs dissociation zone showed significant redistribution and discontinuity of stress. Specifically, distinct stress concentration and corresponding large deformation occurred in the build-up section of the horizontal well, which was thus prone to suffering shear failure. Moreover, apparent end effects occurred at the end of the horizontal well section and might cause the deformation and failure of the casing structure. Therefore, it is necessary to take measures in the build-up section and at the end of the horizontal section of the horizontal well to prevent damage and ensure the wellbore safety in the long-term NGHs exploitation.©2022 China Geology Editorial Office.