物理法随钻防漏堵漏机理的数值模拟研究

Numerical Simulation to Physical Lost Circulation Prevention While Drilling

物理法随钻防漏堵漏技术能有效控制和处理井漏事故,尤其对渗透性漏失和裂缝性漏失有较好的防漏堵漏效果。以Realizableκε紊流模型为基础,根据流体动力学理论建立了在旋转射流作用下环空流场的数学模型,分析了相应的边界条件,进行了网格划分,使用CFD软件Fluent模拟计算了物理法随钻防漏堵漏时的流场。模拟结果和试验结果基本相似,在实际环空返速下,侧向射流受到的干扰较小,并有很好的堵漏效果。模拟结果为物理法随钻防漏堵漏钻井水力参数设计、井底水力能量分配提供了理论依据。

Lost circulation has always been an urgent technical problem to be solved during drill ing. The physical lost circulation prevention can effectively control and manage well leakage accident, espe cially to permeable leakage and fissured leakage. Based on the reliable κ-ε turbulent model, a mathematical model for annulus flow field under rotating jet is created according to computational fluid dynamics （CFI） . The boundary condition was analyzed. A CFD software, Fluent, was used to simulate the flow field when using physical lost circulation prevention. The agreement between the calculated data and the experiment data indicates that the interference affecting the cross range jet is small and has good lost circulation pro vention under annular velocity. This model provides a theoretical basis for the design of drilling hydraulic parameters and hydraulic energy distribution.