抗高温水基钻井液超高温高压流变性研究

Rheological Properties of High-Temperature Water Based Drilling Fluids at High Temperature and High Pressure

为了解超高温高压条件下钻井液的流变规律,采用M7500型超高温高压流变仪测定了胜科1井四开井段抗高温钻井液的超高温高压流变性并进行了分析研究。试验结果表明,抗高温钻井液的表观黏度、塑性黏度和动切力随温度的升高而降低,随压力的增加而增大;温度对流变性的影响远比压力的影响大,但随着温度的升高,压力的影响逐渐增大。流变曲线拟合结果表明,赫切尔-巴尔克莱模式能够比较准确地描述超高温高压条件下抗高温钻井液的流变性。在大量现场钻井液流变性试验的基础上,运用回归分析方法建立了能够准确预测井下超高温高压条件下钻井液表观黏度的数学模型。该研究为超高温钻井液技术在胜科1井的成功应用提供了理论指导。

For the purposes of understanding the rheological characteristics of drilling fluids at ultra high temperature and high pressure, the rheological properties of high temperature water based drilling fluids used in Shengke-1 Well at ultra-high temperature and high pressure were investigated using M7500 HTHP rheometer. The experimental results indicate that strength decrease with the increase of temperature, while the apparent viscosity, plastic viscosity, and gel increase with the increase of pressure. The re sults indicate that the effect of temperature on rheological property of drilling fluids is greater than that of pressure. The effect of pressure increases gradually with the increase of temperature. The rheological curve fitting results suggest that H-B Model is best for HTHP rheological properties. On the basis of nu merous experiments, a model for predicting the apparent viscosity and plastic of high temperature drilling fluids at high temperature and high pressure was established using the regressive analysis. The results of the present investigation provided theoretical guidance for the successful application of ultra-high temperature drilling fluids in Shengke-1 Well.