泵注反循环岩屑粒径对最低排量的影响实验

介绍了泵注反循环钻井的基本原理和特点。利用泵注反循环岩屑运移模拟实验装置,以清水为循环介质,对6种不同粒径的岩屑上返所需要的最低排量(流速)进行了实验。探讨了最低排量和循环压耗随岩屑粒径的变化规律。实验结果表明:岩屑上返的最低排量和循环压耗随岩屑粒径的增大呈现非线性的增加,当岩屑粒径超过4.75mm后,循环压耗的增幅加大;岩屑在水平段运移所需的最低排量小于在弯曲段和直井段运移所需的最低排量。实验结果为泵注反循环钻井方法的应用和水力参数的优化提供了依据。

An experiment for the effect of cutting diameter on the minimum pump rate in Pump-injected reverse circulation drilling

This paper presents the basic principles and characteristics of the reverse circulation drilling technology with pump-injected reverse circulation. Using the simulation experiment device of cutting transportation in this drilling, with clean water as the circulation medium, we have carried out tests of the minimum pump rates (velocity of fluid) for six kinds of cuttings with different particle diameters. Then we studied the regulations of changes of the minimum pump rates and circulation pressure loss with the particle diameters of the cuttings. The results show that both the minimum pump rate and circulation pressure loss are nonlinearly increased with the particle diameter of the cutting increase. The circulation pressure loss rises more sharply when the particle diameter of the cuttings is large than 4-75mm, and the minimum pump rate of cuttings transported in the horizontal well section is lower than that transported in the bending well section and vertical well section. The experiments results provide a basis for the application of the pump-injected reverse circulation drilling technology as well as for the hydraulic parameter optimization.