Research On Electrical Water Shutoff Device Monitoring And Fault Diagnosis System

With further exploration and development of oil fields, the water in the product liquid of the oil well gradually increased, which reduces recovery factor of oil field. In order to stabilizing oil production by water control and improve water flooding efficiency, separate-layer water shut off and production have already been gradually expanded. Chemical plugging, mechanical plugging and many other plugging methods are put into practical use. But because of the bad effect, the complex structure, and high maintenance cost, the traditional method can’t meet the need of frequent exchange of wells. Therefor, it’s very necessary to design a water plugging technology which is suitable for oil wells with water.The control system of electrical controlling quantitative water shutoff system with fault diagnosis function has been designed in this paper. This system realizes remote control based on power line communication, regulate the value of water shutoff, and monitor the state of oil reservoir parameters and fault state.The design scheme of host computer and underground controlling system is introduced in this paper. Host computer is designed to be a portable diagnosis instrument, which is composed of the controlling software and panel. Controlling software is a control platform based on Labwindows/CVI with function of displaying, controlling and storage. The panel is provided with a power and serial signal interface, voltage monitoring instrument and adjusting knob. In terms o f underground controlling system, motor closed-loop control system is designed to be consists of ATmega16microprocessor and linear resistor displacement sensor. In addition, the sensors that can be suitable for high temperature and high pressure environment, are selected to monitor the reservoir pressure, the temperature and humidity value.Signal of the system is transported by single core cable based on power line communication. The frequency domain model of single core cable is est ablished, by which the transmission characteristic is analyzed. Based on FSK modulation, HLPLC520is selected to build the modulation and demodulation circuit. Considering the requirements of communication stability, the communication protocol is designed.In addition, according to the fault classification, the fault diagnosis circuit is established, by which the fault feature can be obtained, and the type of fault can be determined. The state of fault will be transformed to host computer, realizes the alarm function.Finally, in order to ensure the system can work stably in high temperature and high pressure environment, reliability treatment is proposed in this paper in three aspects: hardware design, circuit design and thermal treatment. Through simulatio n experiments, the reliability of control system is verified.