Design Of LVDT Displacement Measurment Device With A Protective Barrel For Downhole Sliding Valve

Beacuse of installing sensors and formation fluid control valves downhole,the intelligent well system can monitor the reservoir dynamics and control the formation fluid dynamics in real time.Intelligent completions have been paid more attention,which their high production efficiency and ultimate recovery factor.The Inflow Control Valve is the key device of the intelligent well system.It automatically controls the premise of real-time and accurate measurment of downhole valve displacement.Direct at complex downhole working conditions,contactless measuement device for formation fluid control valve displacement with the function of downhole fluid erosion protection is developed.Main research contents and stage research results are as follows:1^st.A Linear Variable Differential Transformer displacement sensor will fail the coils function,on the account of the downhole fluid erosion.Therefore the technical measures of adding metal protective sleeve to the sensor coils is proposed.Then the sensors coil winding and parameter design,sensor core structure design and material selection design are completed.Finally,a Linear Variable Differential Transformer displacement measurment sensor for downhole sliding valve with a measuring range of 265mm and prevent fluid erosion is completed.2^nd.Considering the working environment requirements of high temperature and small space,a batch of core chips with small package size and high working temperature were screened,then the hardware and software design of the electronic system of the displacement measurment for downhole sliding valve was completed;The relationship between the displacement of the iron core and the output signal of the sensor at different temperatures is experimentally studied,and then a displacement measurment sensor of piecewise broken line approximation temperature compensation method is proposed.3^rd.According to the communication requirements between the displacement monitoring system and the downhole displacement measurement system,the RS458 bus communication network of the displacement measurment device for downhole sliding valve device was designed,and the software and hardware design and debugging are completed.Based on Lab VIEW,the opening monitoring software with throttle gear and ICV displacement display is designed.4^th.The assembly of the displacement measurement sensor for downhole sliding valve,displacement measurement electronic system and ground monitoring system is completed,and an engineering prototype of well sliding sleeve valve opening monitoring device with accurate measurement and ground monitoring function is made.The engineering prototype is tested results show that the downhole displacement measurement circuit can be installed in the electronic sealed cabin with a width of diameter of28mm and a height of 15mm.The displacement measurement and data transmission function are normal within the range of temperature from normal temperature to 105 degrees,and the error of displacement measurement is less than 10 percent.The ground displacement monitoring interface can obtain and display the data uploaded by the downhole displacement measurement system in real time.The function and performance of the engineering prototype meet the design requirements.The research work provides a useful reference for the engineering design and application of Inflow Control Valve.