Experimental Analysis Of Sand Signal Characteristics And Establishment Of Model For Sand Production

At present,real-time sand production monitoring technology based on sand signal acquisition and analysis is one of the main means to obtain sand production information of oil Wells.In the process of sand production monitoring,the acquisition of vibration signal characteristics of sand hitting the pipe wall and the establishment of sand production model are of great significance for guiding and optimizing sand control method,providing technical reference for sand production,formulating reasonable production plan,optimizing oil well productivity and prolonging economic development cycle of oil and gas fields.This paper investigates the research status of sand production monitoring methods and equipment at home and abroad,and summarizes the methods for acquisition of sand monitoring signals and the model of solid phase mass flow.Based on the engineering practice,the indoor simulated sand monitoring platform was improved.The impact contact process between the particles and the flat plate was analyzed based on Hertz theory.The influence of fluid viscosity on the contact impact stress of the particles was studied by using Comsol.The grit impact plate experiment was designed.The vibration signals of sand impact plate by different meshes sand,different impact heights and different mixing ratios sand were obtained,and the main frequency and its influencing factors of sand impact signal were analyzed by time-frequency analysis method.The method of liquid-solid energy difference is used to establish sand production model,and the indoor experiment under different working conditions is designed to verify the model.The improved liquid-solid two-phase flow simulation monitoring experimental platform effectively reduces the system mechanical noise signal and solves the constant demand of circulating fluid temperature.Base on the vibration principal frequency calculation formula of the particle impact contact plate and the experimental analysis of sand impact plate vibration signal,it is obtained that the main frequency of the sand signal is proportional to the number of sand meshes.The initial velocity of the sand impacting the pipe wall has little influence on the main frequency of the sand signal.The effection of liquid film viscosity on particle contact stress transmission was given by the fluid-solid physics coupling in a range of 1-246 m Pa·s.Base on the vibration signal energy calculation formula,the expression of the relationship between the impact energy of the pure fluid and the flow velocity is obtained,and the relationship between the impact vibration energy and the impact velocity of the grit under different mass flow rates is obtained.The vibration energy difference method is used to reduce the interference of background fluid noise,and the model of sand production amount under water and oil flow is obtained.The results of laboratory experiments show that the average error of sand production under clear water conditions with different flow velocities is 6.15%,the average error of sand production under clear water conditions with different meshes of sand is10.15%,and the average error of sand production under oil flow conditions with different viscosities is 10.56%.The calculated results of the model are in good agreement with the experimental results,which is of great reference value to the improvement of sand production monitoring methods.