摘要：ECD is an important parameter to judge whether there is a risk of well leakage during cementing in deep formation,and it is the key to guarantee cementing safety for accurate prediction and control of annulus ECD.The traditional ECD prediction model only gives a single value curve,but in the actual construction process,due to the influence of temperature and pressure on the change of the physical parameters of the fluid,as well as the impact of the measurement accuracy of relevant parameters,the cementing annulus ECD at this time has some uncertainties.Therefore,the traditional ECD singlevalue calculation model has some errors.In this paper,the uncertainty of annulus ECD in He-Ba fluid is studied based on the uncertainty theory.Is given with a confidence interval of annulus ECD range,and connecting with the southern region is analyzed,the corresponding with the commercial software and actual wellhead pressure were analyzed,the results show that the use of this evaluation method can reasonable and effective analysis of potential risk of lost circulation,in order to ensure the security of the cementing cement construction to provide theoretical basis and technical guidance.
