Design Of Moisture Content Detection System For Crude Oil Based On Conductivity Method

The water content of crude oil has a direct impact on crude oil production,dehydration,gathering and transportation,metering,sales,refining and other links.In the process of crude oil production,storage and transportation,it is required to detect the water content of crude oil.The on-line detection of water content of crude oil is of great significance for determining the water and oil producing horizon,estimating the crude oil production and predicting the development life of oil wells.At the same time,accurate and timely online detection data of water content of crude oil can reflect the working state of oil wells,which plays an important role in reducing energy consumption,reducing costs and realizing automatic management of oil fields.In this paper,the development status of water content meter,conductivity meter and electrode sensor at home and abroad is analyzed,and the influencing factors of solution conductivity measurement are studied.A detection system of water content in crude oil based on conductivity method is designed.By using the selected frequency end of the oscillating circuit with AGC stable amplitude,the conductivity of the solution is obtained by measuring the frequency of sine wave generated by the oscillating circuit of the Vincent bridge,and the water content of the solution is obtained by the relationship model between the volume fraction of Maxwell and the mixed conductivity.The detection system uses STM32F103 as the processor,which has the functions of data display,timing storage and data exchange with other devices.The hardware circuit is divided into conductivity measurement probe,information acquisition circuit,waveform sorting circuit and control circuit.The conductance measurement probe adopts DJS-10 C,the information acquisition circuit adopts Vincent bridge oscillation circuit with AGC amplitude stabilization,and the waveform sorting circuit adopts Schmitt trigger.The control circuit mainly includes clock,communication,display,storage and other circuits.The detection system displays the measurement results on the PC through serial port communication,and also on the capacitance screen.After software debugging and hardware debugging,the stability of the system is good,and after calibration,the accuracy of the measurement system is 2% FS,which fully meets the needs of engineering measurement.