低渗透储层水平井—直井联合布井极限注采井距研究     

侯晓春  陆程  蔡文  郑兴范 《现代地质》2008,22(1)

低渗透储层水平井—直井联合布井技术具有广泛的应用前景,其布井方式至关重要。首先利用劈分流场的方法直观地给出常规储层水平井—直井联合布井的产能评价方法;然后针对低渗透储层的渗流特点,在考虑启动压力梯度条件下建立新的井网渗流物理模型并求解得到产能评价公式;最后经分析计算给出启动压力梯度影响的面积井网极限注采井距关系曲线。研究结果为低渗透储层部署水平井—直井联合井网提供理论依据。  相似文献   

Application of X-ray computed tomography for analyzing cleat spacing and cleat aperture in coal samples   总被引：2，自引：2，他引：2  

S. Mazumder  K.-H.A.A. Wolf  K. Elewaut  R. Ephraim 《International Journal of Coal Geology》2006,68(3-4):205-222

New techniques to determine distributions of cleat aperture, cleat orientation and cleat spacing from CT scans have been developed. For cleat orientation and spacing distributions, two different coal blocks were scanned. The CT scans have been analyzed for the three orthogonal directions. Histograms of the cleat orientations are bimodal, expressing the typical cleat texture of face and butt cleats and bedding perpendicular relaxation fractures. Deviations up to 20° from the peak values in the cleat orientation distributions were used as input for automated image analysis of cleat spacing. Distributions of the cleat spacing measurements are related to the face and butt cleat directions. The term “relevant cleat length” is introduced as a measure to extract the amount of cleat length involved with the cleat spacing measurements. The ratio ranges from 0.03 to 0.38 and expresses the difference in cleat texture in both samples. Cleat spacing versus relevant cleat length shows sample specific patterns for face cleat, butt cleat and bedding. To describe cleat aperture quantitatively, peak height and missing attenuation have been used. The image of a cleat was seen as a convolution of a rectangular fracture profile with a Gaussian point spread function.  相似文献   

Drainage spacing regularity on a fault-block: A case study from the eastern Ruahine Range     

Heather Purdie  Martin Brook 《New Zealand geographer》2006,62(2):97-104

Abstract:  Recent research has indicated river basin outlets draining linear sections of large, uplifting mountain belts often show a regularity of spacing, transverse to the main structural trend. A morphometric analysis of part of the Ruahine Range, on the North Island was undertaken to test whether drainage regularity may exist in smaller, younger mountain ranges. The ratio, R , of the half-width of the mountain belt, W , and the outlet spacing, S , was used to characterize drainage networks on the eastern side of the range. The spacing ratio for the range of 1.31 is lower than R results from studies of larger mountain belts ( R  = 1.91–2.23). We suggest the cause of this lower ratio is related to eastward migration of the Ruahine drainage divide.  相似文献   

基于Matlab的水准点稳定性分析   总被引：1，自引：0，他引：1  

姚占派  缑忠才 《现代测绘》2004,27(2):25-27

通过使用Matlab功能强大的数学软件，应用于测量工程的数据处理。具体解决变形监测中水准点是否稳定的判定问题。并通过计算实例说明其可行性和优越性。  相似文献   

五圆柱体结构群绕流特性及互扰效应研究     

涂佳黄  张志豪  曹波  肖毅凡  梁经群 《海洋工程》2020,38(1):101-110

基于Fluent流体计算平台,运用大涡模拟方法对亚临界雷诺数Re=3900下“X”形排列五圆柱体结构群三维绕流特性进行研究,主要分析来流攻角α与间距比L/D两个关键参数对五圆柱体结构群的尾流区三维涡结构演化与流体力系数的影响,并揭示其内在流动互扰机理。研究表明:来流攻角和间距比的变化对五圆柱体结构群流动控制及互扰效应的影响显著。在小间距比工况下,观察到柱体群间隙区域内流体高速流动的现象,导致五圆柱体之间的互扰作用十分强烈。间隙流对中间圆柱体和下游圆柱体有较强的冲击作用,对其表面的流体力分布特性有显著的影响。另外,大间距比工况下,当α=0°与L/D≥5.0工况时,柱体群尾流效应强于其间隙流效应。当α=22.5°与L/D=7.0时,位于下游与中间处的圆柱体流体绕流特性存在较大差异。而当α=45°与L/D≥6.0时,位于上游与中间处的圆柱体尾流区均会产生正负交替的漩涡结构。  相似文献   

不同结构林带防风效能风洞模拟     

李晓烨  王克俭  谷建才  刘启国  崔严 《中国沙漠》2019,39(6):118-125

防风林带结构是影响防风效能的主要因素。建立不同宽度、不同株行距林带防风效能与林带后距离之间的统计模型,可以为防风林建设提供指导性意见。通过风洞实验,在11 m·s^-1风速下,对4种宽度、5种株行距林带的背风面0~10H（H为林带高度）的风速进行测定,采用曲线参数估计法、傅立叶模型、SSF模型（Sum of Sin Functions）,构建了不同结构林带防风效能与林带后距离间的统计模型。结果表明：傅立叶模型拟合不同宽度林带的防风效能与林带后距离的关系效果最优,可决系数（R²）均在98%以上;SSF模型拟合不同株行距林带的防风效能与林带后距离的关系效果最优（R²>0.98）。根据构建的统计模型,风速为11 m·s^-1左右时,林带宽度8 m（两行一带）的防风林的防风效能存在明显优势;5种株行距的林带中,株行距为8 m×8 m的防风林带本试验条件下防风效果最好。  相似文献   

Bragg reflection of water waves by multiple floating horizontal flexible membranes with submerged rectangular bars on the seabed     

《Applied Ocean Research》2019

Bragg reflection of water waves by multiple floating horizontal flexible membranes is investigated based on the linear wave theory and the assumption of small membrane response. Under the floating horizontal membranes, periodical submerged rectangular bars are arranged on the flat seabed. The total reflection and transmission coefficients are obtained by using the eigenfunction expansion method and the wide spacing approximation. The calculated coefficients are validated with the results available in the literature, which shows that the present method is applicable. The characteristics of Bragg reflection are systematically investigated by changing various parameters including the height of the rectangular bars, the number, the tension, the spacing, and the length of the flexible membranes. The results can help designing multiple floating horizontal flexible membranes as effective floating breakwaters by taking advantage of Bragg reflection.  相似文献   

不同排列方式和间隙比下双圆柱流致振动特性研究   总被引：1，自引：0，他引：1  

刘巨保  杨明  岳欠杯  丁宇奇  姚利明 《海洋工程》2018,36(4):105-113

采用基于ALE的流固耦合分析方法,将圆柱体振动模型简化为平面双自由度质量-弹簧-阻尼系统,进行了计算参数无关性分析。对不同θ角和间隙比T下的双圆柱流致振动进行数值模拟,并与单圆柱振动计算结果进行比较,得到了不同θ角和间隙比T下中心圆柱的升阻力系数、流场分布和运动轨迹变化情况。通过分析发现小间隙比下由于两圆柱间的相互干扰,改变了中心圆柱的尾涡结构,导致了升力和阻力系数随不同θ角而发生变化;小间隙比下由于两圆柱间的相互干扰影响,均使中心圆柱的轨迹在不同θ角下发生了较大的变化,顺流向的振动频率与单圆柱振动时相比出现了多倍频,导致其运动轨迹发生了变化。  相似文献   

窄小砂体油田注采系统调整技术研究     

许洪东 《世界地质》2001,20(2):148-154

油田水下窄小分流砂体进入中高含水期后,由于现井网对油层的水驱控制程度低,制约了分层注水调整技术优势的发挥,影响了开发效果。提出一套适合窄小砂体油田注采系统的调整,即以单砂体研究为基础,“分砂体、分阶段”采用层次分析法和模糊综合评价方法的“全方位优化转注方案 ”,对原井网进行了加密调整、细分注水。合理的注采系统调整是控制油田产量递减、提高水驱油采收率的有利措施。  相似文献   

The geomorphological significance of airflow patterns in transverse dune interdunes   总被引：1，自引：0，他引：1  

M.C. Baddock  I. Livingstone  G.F.S. Wiggs   《Geomorphology》2007,87(4):322-336

  相似文献