煤层气精准排采监控系统

Monitoring system for accurate coalbed methane drainage

针对现有煤层气排采系统存在控制精度低、劳动强度大、不能按照排采规律进行作业、生产成本高等问题,设计了一套煤层气精准排采监控系统。该系统选用STM32F107Connectivity互接系列单片机作为控制中心,利用现场采集单元实时采集井底流压、温度、套压值、频率等信号,并通过RS485通信接口、4~20mA模拟量接口将信号传输至控制中心。通过比较井底流压实测值与给定值后得到偏差信号,根据偏差信号,控制中心通过排采控制算法实时控制变频器输出频率,进而调节排采设备的运转速度,实现井底流压的自动闭环控制。采用4G无线传输模块将控制调节命令发送至排采控制单元,实现排采过程的实时监测与控制。现场测试结果表明:该系统能够按照实时排采制度执行作业,井底流压调节准确,平均误差在0.5%以内,达到了煤层气井精准排采的要求。

In view of problems existing in conventional coalbed methane drainage system,such as low control accuracy,high labor intensity,inability to operate according to drainage and extraction rules,and high production cost,a monitoring system for accurate coalbed methane drainage was designed.The system uses STM32F107 Connectivity series microcontrollers as the control center,and adopts field acquisition units to collect real-time downhole flow pressure,temperature,casing pressure value,frequency and other signals,and transmits the signals to the control center through RS485 communication interface and 4-20 mA analog interface.The deviation signal is obtained by comparing the measured value of downhole flow pressure with the given value.According to the deviation signal,the control center controls the output frequency of the converter in real time through the drainage control algorithm,and then adjusts the operation speed of the drainage equipment to realize the automatic closed-loop control of downhole flow pressure.4 Gwireless transmission module is used to send control and adjustment command to drainage control unit to realize real-time monitoring and control of the drainage process.The field test results show that the system can execute the operation according to the real-time scheduling system,the regulation of downhole flow pressure is accurate,the average error is within 0.5%,which can meet the requirements of accurate coalbed methane drainage.