摘要
The solid weighting material in a high-density workover fluid is prone to static sag.Existing experi mental methods cannot predict the parameters of the settling stability of workover fluids at high tem perature and high pressure(HTHP).Therefore,in this study,static settlement experiments were carried out using a novel experimental setup.The experimental setup enables the measurement of the density profile of heavy workover fluids at HTHP.A multi-parameter correlation equation between the sag factor and particle diameter,particle density,base fluid density,workover fluid density and rheological pa rameters,aging time,temperature,and pressure was obtained using dimensional analysis and multi variate nonlinear regression methods.The results reveal that the settlement stability of the workover f luid decreases with the increase in temperature and pressure.Based on the multi-parameter correlation,the predicted and the measured values were compared and verified.The error between the predicted value and the measured value was within 5%.The average prediction error was 1.68%,and the maximum prediction error was 3.8%.These results reveal that the model proposed in this study can effectively predict the static sedimentation stability of the solid weighted Polysulfonate workover fluids.Further more,the proposed correlation can guide the properties adjustment of the workover fluids to achieve the required sag stability.This work provides a new approach to predict and control the sag stability of the solid weighted workover fluids.
基金
financed by the Natural Science Foundation of Sichuan Province (No. 2024 NSFSC0204).
