钻井液流动稳定性判别新方法

在钻井，固井作业中工作液基本都符合非牛顿流体的本构模型。因而研究非牛顿流体的稳定性判别方法对于科学设计钻井，固井等水力参数。避免在作业中出现不希望出现的流态具有重要意义。在全面分析了现有流体稳定性判别方法基础上，提出了应用圆管和环空断面平均剪切率与平均剪切力而得断面平均视粘度的方法，应用该方法建立了一种新的判别非牛顿流体稳定性的方法。利用文献中的实验数据对非牛顿流体稳定性判别新方法的验证结果表明，该方法符合流体流动本质，并且与雷诺数定义的本义相符，比普通方法相对误差小，岢以用于钻井水力参数设计施工。

A new method for determining drilling fluid flow stability

As most of the working fluids in drilling or cementing conform with non-Newtonian constitutive model, it is important to study the methods of determining non-Newtonian flow stability in designing advisable hydraulic parameters of drilling and cementing and preventing inexpedient flow state during working. Thus, a new method for discriminating non-Newtonian flow stability has been established based on roundly analyzing present methods. The new method considers that average apparent viscosity on the section of pipe and annular flows should be obtained according to the average shear rate and shearing force on the section of the flows. The new method has been examined by using published experimental data and the issues show that it conforms to flow essence of fluids and agrees with original meaning of Reynolds number. It can be used in designing hydraulic parameters for drilling.