用密度波特征波速判定环空多相流流型的转变

发布时间：2018-03-25 13:03

本文选题：钻井　切入点：密度波　出处：《天然气工业》2017年11期

【摘要】：钻井环空多相流流型判定目前主要依靠经验公式,存在着一定的误差。为此,考虑钻井液相湍动、脉动速度、虚拟质量力、斯托克斯力、相界面动量传递等因素,在双流体模型的基础上,建立了密度波特征波速判定环空多相流流型转变的模型,并利用小扰动线性法,通过编程计算求解。研究结果表明:(1)由所建模型计算的数据与前人密度波不稳定判断流型结果一致;(2)虚拟质量力对密度波特征波速判断流型的影响较大,随虚拟质量力系数增大,泡状流向弹状流转变的空隙率增大;(3)随井深增加,分散气相密度增大、气相与钻井液相相对密度增大、界面膜稳定性增强,分散气相液滴不易发生聚集,泡状流向弹状流转变空隙率增大;(4)密度波一次不稳定性导致分散气相从泡状流聚合为弹状流,密度波二次不稳定现象导致气相继续聚合,逐渐形成连续的气体环状,从而发生弹状流向环状流转变,密度波的二次不稳定现象多发生在井口环空段。结论认为,利用密度波特征波速来判定井筒流型转变是可行的。
[Abstract]:At present, the determination of multiphase flow pattern in annular annulus mainly depends on empirical formula and there are certain errors. Therefore, considering the factors such as fluid phase turbulence, pulsation velocity, virtual mass force, Stokes force, phase interface momentum transfer and so on, On the basis of the two-fluid model, a model for determining the flow pattern transition of annular multiphase flow with the characteristic wave velocity of density wave is established, and the small perturbation linear method is used. By programming, the results show that the data calculated by the established model are consistent with the previous results of judging the flow pattern by the density wave instability. (2) the virtual mass force has a great influence on the velocity of the characteristic wave of the density wave. With the increase of the virtual mass force coefficient, the void ratio of bubbly flow to slug flow increases with the increase of well depth, the density of dispersed gas phase, the relative density of gas phase and drilling fluid, and the stability of the interfacial membrane. Dispersed gas droplets are not easy to aggregate, and bubble flow flow transition void ratio increases. The primary instability of density wave leads to dispersed gas phase polymerization from bubbly flow to slug flow, and the secondary instability of density wave leads to gas phase continuing polymerization. A continuous annular gas flow is gradually formed, which leads to the slug flow to the annular flow, and the secondary instability of the density wave occurs mostly in the annulus of the wellhead. It is concluded that it is feasible to use the characteristic wave velocity of the density wave to determine the wellbore flow pattern transformation.
【作者单位】：成都理工大学能源学院;中国石化西南油气分公司勘探开发研究院;中石化西南石油工程有限公司技术发展处;中石化西南石油工程有限公司钻井工程研究院;长江大学石油工程学院;
【基金】：国家自然科学基金项目“H_2S/CO_2溶解度测试、预测及其与套管完整性的相关性研究”(编号:51274170)
【分类号】：TE24

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