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基于CFD-DEM算法的压裂支撑剂缝内铺砂规律
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作者 郭慧娟 高畅 +4 位作者 韩金井 范应璞 Guodong Zhan 王宏伟 张金亚 《石油机械》 北大核心 2023年第6期104-111,共8页
为优化页岩气支撑剂的输送性能,采用计算流体力学-离散元(CFD-DEM)耦合方法对中等矩形裂缝进行数值模拟,考虑了重力、浮力以及颗粒-颗粒、颗粒-流体、颗粒-壁面之间的相互作用,采用单一因素控制变量法对支撑剂密度、携砂液流速、支撑剂... 为优化页岩气支撑剂的输送性能,采用计算流体力学-离散元(CFD-DEM)耦合方法对中等矩形裂缝进行数值模拟,考虑了重力、浮力以及颗粒-颗粒、颗粒-流体、颗粒-壁面之间的相互作用,采用单一因素控制变量法对支撑剂密度、携砂液流速、支撑剂质量分数以及压裂液黏度4个影响因素进行评价。研究结果表明:降低支撑剂与压裂液之间的质量分数差,可以提高86%的输送距离,确保支撑剂运移至裂缝深处;较高的携砂液流速会增大支撑剂的流化度,在距离入口较远处沉降;由于液体对颗粒的曳力作用,一定程度地提高压裂液的黏度会使支撑剂填充层的液体体积分数增加23%;增大支撑剂的砂比可以提前达到支撑剂的“平衡高度”,但在入口处有堆积,容易产生卡泵现象,可以采取变速加砂和梯度混砂的方式提高支撑剂的输送效果。研究结果可为现场压裂作业提供参考。 展开更多
关键词 水力压裂 支撑剂输送 CFD-DEM 缝内铺砂 固液两相流
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水力振荡器数值计算研究 被引量:4
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作者 郭慧娟 Guodong Zhan +1 位作者 Timothy Eric Moellendick 明瑞卿 《石油机械》 北大核心 2020年第3期19-29,共11页
目前尚未开展水力振荡器在改变特定参数和参数间在某种最优配合条件下能否得以优化的研究,制约了该工具的进一步完善。针对该问题,利用SolidWorks软件对水力振荡器的各部分结构进行三维建模,在ICEM CFD中进行网格划分,将网格导入ANSYS ... 目前尚未开展水力振荡器在改变特定参数和参数间在某种最优配合条件下能否得以优化的研究,制约了该工具的进一步完善。针对该问题,利用SolidWorks软件对水力振荡器的各部分结构进行三维建模,在ICEM CFD中进行网格划分,将网格导入ANSYS CFX进行数值计算与分析。研究结果表明:当流体通过水力振荡器时,旋转部件的运动使得流体动能增加,在流动过程中流体的动能重新转换为压能,使得该工具沿轴向正方向产生持续轴向力推动钻头做功;动静干涉作用和交界面速度变化所造成的流体震荡使得静止域产生剧烈的轴向和径向周期振动;大流量工况下轴向推力均值更大,轴向和径向振动也更为剧烈;在持续轴向推力和大幅度轴向振动推动下,该工具对钻柱施加周期性轴向振动和钻压并稳定推进。研究成果可为提高水力振荡器优化设计与敏感性分析水平提供相应的理论支撑。 展开更多
关键词 水力振荡器 流体力学 振动减阻 机械钻速 数值计算
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Multi-scale elastoplastic mechanical model and microstructure damage analysis of solid expandable tubular 被引量:1
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作者 郭慧娟 刘应华 +2 位作者 苏义脑 张全立 詹国栋 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第10期336-348,共13页
We present an in-depth study of the failure phenomenon of solid expandable tubular (SET) due to large expansion ratio in open holes of deep and ultra-deep wells. By examining the post-expansion SET, lots of microcrack... We present an in-depth study of the failure phenomenon of solid expandable tubular (SET) due to large expansion ratio in open holes of deep and ultra-deep wells. By examining the post-expansion SET, lots of microcracks are found on the inner surface of SET. Their morphology and parameters such as length and depth are investigated by use of metallographic microscope and scanning electron microscope (SEM). In addition, the Voronoi cell technique is adopted to characterize the multi-phase material microstructure of the SET. By using the anisotropic elastoplastic material constitutive model and macro/microscopic multi-dimensional cross-scale coupled boundary conditions, a sophisticated and multi-scale finite element model (FEM) of the SET is built successfully to simulate the material microstructure damage for different expansion ratios. The microcrack initiation and growth is simulated, and the structural integrity of the SET is discussed. It is concluded that this multi-scale finite element modeling method could effectively predict the elastoplastic deformation and the microscopic damage initiation and evolution of the SET. It is of great significance as a theoretical analysis tool to optimize the selection of appropriate tubular materials and it could be also used to substantially reduce costly failures of expandable tubulars in the field. This numerical analysis is not only beneficial for understanding the damage process of tubular materials but also effectively guides the engineering application of the SET technology. 展开更多
关键词 solid expandable tubular(SET) material microstructure damage multi-scale elastoplastic model virtual failure
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Is the hardness of material harder than diamond reliable?
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作者 Jin Liu Yongtao Zou +4 位作者 Guodong David Zhan Pei Wang Xiaozhi Yan Duanwei He Liping Wang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2023年第13期111-117,共7页
With the development of new synthesis methods and chemistries,a number of new superhard materials have been reported to be harder than diamond.While such materials are highly desirable due to their wide-ranging applic... With the development of new synthesis methods and chemistries,a number of new superhard materials have been reported to be harder than diamond.While such materials are highly desirable due to their wide-ranging applications,there are some inherent uncertainties in the methods utilized to determine and define the hardness of such materials.In this paper,we employed the standard Vickers diamond indenter and substitute indenters with the same shape to measure the hardness of nine ceramics and superhard materials within well-defined criteria and methodology,for the assessment of consistency in the hardness testing.The findings and the developed testing method in the current study have broad implications in characterizing new and emerging superhard materials,leading to new discoveries. 展开更多
关键词 Vickers hardness Superhard materials Emerging materials APPLICABILITY
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