颗粒基随钻堵漏钻井液流变参数测算方法

Calculation of the Rheological Parameters of Drilling Fluids with Particle Lost Circulation Materials

随钻堵漏材料的加入必然会对钻井液的流变性能产生影响。针对旋转黏度计标准测量间隙过窄而无法测量含粗粒堵漏材料钻井液流变性能的问题,利用实验测试与反问题数学模型相结合的方法,建立了颗粒基随钻堵漏钻井液的流变参数测算方法。利用建立的测算方法,将旋转黏度计的读数和转速数据转化为剪切应力与剪切速率形式。结果表明,建立的流变参数测算方法可靠性强,含颗粒随钻堵漏材料的KCl聚合物钻井液的流变曲线符合H-B模型,增加颗粒堵漏材料会显著影响钻井液流变参数。颗粒材料粒径和加量对钻井液的流变特性均有明显影响,测算随钻堵漏钻井液流变参数时应予以重视。

Addition of lost circulation materials(LCMs)while drilling in a drilling fluid will inevitably affect the rheology of the drilling fluid in circulation.The clearance between the rotator and the stator of an API standard viscometer is too narrow to measure the rheology of a drilling fluid containing coarse LCMs.To address this problem,a method of calculating the rheological parameters of a drilling fluid containing particle LCMs was developed based on the combination of laboratory experiment and inverse problem mathematical model.Using the method,the viscometer readings and the rotational speeds can be turned into a relationship between shear stress and shear rate.Laboratory experimental results showed that the calculation method is reliable,a KCl-polymer mud containing particle LCMs had a rheological curve conforming to H-B model.Increasing the concentration of the LCMs in the drilling fluid significantly affected the rheological parameters of the drilling fluid.Attention should be paid to the fact that particle size and concentration of LCM both have significant effects on the rheology of the drilling fluid.