深井油基钻井液在高温高压下表观粘度和密度的快速预测方法

Methods for Quickly Predicting Apparent Viscosity and Density of Oil-Based Drilling Fluids under HTHP Conditions

深井油基钻井液在应用中一个重要的技术难题是如何对高温高压条件下不同井深处的油基钻井液流变参数和钻井液密度进行准确的预测,从而采取相应的技术措施,使之具有良好的携岩能力,并使钻井液密度始终保持在适宜范围。在前人工作基础上,通过对试验数据进行多元回归数学处理,分别建立了预测高温高压下油基钻井液表观粘度和密度的数学模型,并提出了相应的快速预测方法。室内试验结果表明,表观粘度的预测值与实测值的吻合情况良好,相对误差可控制在±10%以内。对钻井液密度预测值的验证有待于今后进行。

One of the important technical issues presented while using oil-based drilling tired m deep wells is how to correctly predict rheological parameters and density of oil-based drilling fluid under HTHP conditions so as to enable the drilling fluid to have good performance in carrying the cuttings to surface and keep the density in a proper range by taking corresponding measures. In this study, the mathematical models for predicting the apparent viscosity and density of oil-based drilling fluids have been established respectively, and the corresponding prediction methods have also been provided by adopting the regression procedures on the basis of the previous research work. Lab tests show that the predicted values of apparent viscosity are in good agreement with the measured values with a relative error of within ±10%. The examination for predicted values of density of oil-based drilling fluids will be done in the further work.