基于CFD-DEM耦合模型的大粒径非常规岩屑颗粒运移规律研究
发布时间：2019-05-22 01:36
【摘要】：采用CFD-DEM耦合计算模型,利用DEM软件建立大粒径(2 cm)、非球体岩屑颗粒的离散元模型,与FLUENT实现无缝耦合并行计算,颗粒间相互作用采用Hertz-Mindlin弹性接触模型,对大粒径的、非常规岩屑颗粒在水平井段的运移规律进行了数值模拟计算。基于钻井实测数据,建立水平井段环空内含不同形状(片状,立方体状及球状)相同等效球体粒径颗粒的计算模型,展示了井眼环空内颗粒运移、沉积状态,对环空钻井液流速、不同形状的岩屑颗粒运移速度进行了计算分析,本文还计算得到片状大粒径岩屑含量对钻井液携岩效果的影响规律。结果显示:2 cm等效体积球体粒径的颗粒在井眼环空内的运移状态较差,出现局部堆积;立方体状颗粒的运移效果最差,片状颗粒次之;在所选用计算条件下,片状颗粒含量大于10%时会加剧削弱携岩效果。计算结果可对钻井携岩问题的研究提供一定的参考价值。
[Abstract]:The discrete element model of large particle size (2 cm), non-spherical cuttings) is established by using CFD-DEM coupling calculation model and DEM software, and the seamless coupling parallel calculation is realized with FLUENT. Hertz-Mindlin elastic contact model is used for the interaction between particles. The migration law of large grain diameter and unconventional cuttings particles in horizontal well section is simulated and calculated. Based on the measured drilling data, a calculation model with the same equivalent sphere particle size in the annular space of a horizontal well section (flake, cubic and spherical) is established, which shows the migration and deposition state of the particles in the annular space of the wellbore. The velocity of annular drilling fluid and the migration velocity of cuttings with different shapes are calculated and analyzed. The influence of flake and large diameter cuttings content on the rock carrying effect of drilling fluid is also calculated in this paper. The results show that the particle size of 2 cm equivalent volume sphere has poor migration state and local accumulation in the wellbore annulus, and the migration effect of cubic particles is the worst, followed by flake particles. Under the selected calculation conditions, when the content of flake particles is more than 10%, the effect of rock carrying will be aggravated and weakened. The calculated results can provide certain reference value for the study of drilling rock carrying problem.
【作者单位】： 中国石油大学机电工程学院;海洋石油工程(青岛)有限公司;中国石油大学储运与建筑工程学院;
【基金】：国家自然科学基金(51374228) 中国博士后科学基金(2017M612375)资助
【分类号】：TE243
，
本文编号：2482564
[Abstract]:The discrete element model of large particle size (2 cm), non-spherical cuttings) is established by using CFD-DEM coupling calculation model and DEM software, and the seamless coupling parallel calculation is realized with FLUENT. Hertz-Mindlin elastic contact model is used for the interaction between particles. The migration law of large grain diameter and unconventional cuttings particles in horizontal well section is simulated and calculated. Based on the measured drilling data, a calculation model with the same equivalent sphere particle size in the annular space of a horizontal well section (flake, cubic and spherical) is established, which shows the migration and deposition state of the particles in the annular space of the wellbore. The velocity of annular drilling fluid and the migration velocity of cuttings with different shapes are calculated and analyzed. The influence of flake and large diameter cuttings content on the rock carrying effect of drilling fluid is also calculated in this paper. The results show that the particle size of 2 cm equivalent volume sphere has poor migration state and local accumulation in the wellbore annulus, and the migration effect of cubic particles is the worst, followed by flake particles. Under the selected calculation conditions, when the content of flake particles is more than 10%, the effect of rock carrying will be aggravated and weakened. The calculated results can provide certain reference value for the study of drilling rock carrying problem.
【作者单位】： 中国石油大学机电工程学院;海洋石油工程(青岛)有限公司;中国石油大学储运与建筑工程学院;
【基金】：国家自然科学基金(51374228) 中国博士后科学基金(2017M612375)资助
【分类号】：TE243
，
本文编号：2482564
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