Dynamic Monitoring Method For Viscosity And Density Of Drilling Fluid At Ultra-high Temperature

At present,the most commonly used method is using syringes to measure the density of drilling fluids at different depths,meanwhile the viscosity can only be measured at a single point.Most of the measurements are done manually,including measure viscosity and density.Phase content requires a variety of instruments,which not only costs a lot of manpower and time,but also has relatively large measurement error,so it is difficult to achieve the reproduction of measurement results.In this paper,the traditional methods for measuring the viscosity and density of drilling fluid are studied and summarized.On the basis of theoretical analysis,a system for measuring the viscosity and density of drilling fluid is designed.Full-text research is mainly divided into the following contents:(1)The principle of drilling fluid viscosity and density measurement system was studied.This paper introduces the principle of producing drilling fluid viscosity and density,analyses and compares weighing method,float method,X-ray diffraction method,differential pressure method and tuning fork method in measuring drilling fluid density,analyses and compares capillary method,rotating viscometer method,drop ball method and tuning fork method in measuring drilling fluid viscosity,synthesizes the advantages and disadvantages of measuring drilling fluid viscosity and density,and puts forward optimization.(2)According to the realization of dynamic experimental monitoring of drilling fluid under ultra-high temperature,three experimental ideas are designed:pressure difference method to measure density change during solid-phase settling of drilling fluid and rotary viscometer to measure viscosity change during solid-phase settling of drilling fluid;X-ray diffraction method to realize density change during solid-phase settling of drilling fluid and drop ball method to realize solid-phase settling of drilling fluid.The change of viscosity and density in the process of phase settling and tuning fork method can realize the change of viscosity and density in the process of solid phase settling of drilling fluid.(3)After designing and building experimental equipment and carrying out experiments,the following conclusions are drawn:the experimental results obtained by pressure difference method and rotating viscometer method have poor repeatability,low experimental accuracy and long time for the device to reach equilibrium;the experimental results obtained by X-ray diffraction method and falling ball method have poor fitting results,and can not realize the viscosity and density of drilling fluid in the process of solid-phase sedimentation.Dynamic monitoring;The results of tuning fork method are more accurate,the experimental process is faster,and the operation efficiency of the device is higher.The experimental device for monitoring the viscosity and density in the process of solid-phase sedimentation can be used simultaneously without affecting each other,which overcomes the shortcoming that two sets of equipment must be used to measure the two parameters separately in the existing technology.In this paper,a preliminary study on the measurement of the solid-phase settlement process of ultra-high temperature drilling fluid is carried out,and the prototype of the monitoring system for the solid-phase settlement of ultra-high temperature drilling fluid is designed.The feasibility of the system is verified by the systematic test experiment,which provides a feasible option for the dynamic monitoring.