Research On Real-time Dynamic Analysis Of The System For Pumping Wells

One of the most important processes in current oil production is the pumping method, whose working conditions will directly influence the productivity of the oilfield. In order to enhance the crude oil production, lower the working stress of workers and improve working efficiency and the oil field management levels, this paper based on the GPRS communication technology, puts forward and designed the real-time dynamic analysis system of pumping wells, which can be used to collect and transfer the working conditions of pumping system, draw the dynamometer cards, and monitor the pumping system all the time. Mainly through the direct torque control (DTC) technology, this system can estimate the electromagnetic torque and rotor speed by using electromagnetic torque equation of motors and dynamically estimating speed methods, just needing to measure the voltage and current signals. Then we can calculate the output torque of the motors. According to the power transmitting process and the equilibrium principle of the reducing gearbox, we could calculate the net torque of the reducing gear box and the load torque of the well. Finally, we can use the torque factor of the pumping units to obtain the polished rod load and draw the indicator diagram by connecting polished rod load and rod motion. This system mainly contains three parts: the remote detection terminal unit of pumping, the remote data transmission unit of GPRS, and the data processing unit of monitoring center. The remote detection terminal unit is mainly used to transmit, receive and process the data and control the pumping unit. With the embedded ARM CPU as the core, it could realize the design of the software and the hardware of the well pumping unit's data collection, process the circuit of sensor and signals, and the module of the remote data transmission unit of GPRS. Using the GPRS communication unit, the remote data transfer unit of GPRS can transmission data and be responsible for the communication between terminal detection and monitor center. With the application of Visual C++ and Matlab, the data processing unit of monitoring center can be used for noise-suppressed processing of the signals by the wavelet analysis technology. Then we can get the working conditions of the engine by referring to the DTC, and obtain the indicator diagram by the dynamic and kinetic model. Finally, we can analyze the signals with spectrum analysis technology. Through the practical measure of the experimental data of the Oilfield of Da Gang, the dynamic real-time analysis system of pumping system can precisely reflect the working conditions of pumping unit. And with the fact that we just need to install the sensors used to monitor voltage, current, upper and bottom dead position, pulley speed, the installing process is simple and can be suitable to the harsh conditions of the oilfield, and can monitor the dynamic real-time process of pumping units.