Research On Processing Technology And Application Of Detection Signal For Oil Well Dynamic Liquid Level

The depth of oil well dynamic liquid level is an important data during oilfield production and management.The oil well dynamic level detection uses sound wave to propagate casing annulus,and the dynamic liquid level is detected through the sound wave reflection principle of coupling and liquid level.In the actual oil well dynamic level detection,the sound wave and echo signal are affected by the oil well environmental noise,and the characteristics of the detection signal are difficult to distinguish,resulting in a large error in the calculation result.It is of great significance to improve the detection accuracy of the dynamic liquid level in oil wells by researching the noise reduction,feature extraction and depth calculation of the dynamic level detection signal in the oil well.According to the characteristics of the actual oil well dynamic liquid level detection and signal,article takes the detection signal of the oil well liquid dynamic level as the research object,to build a dynamic liquid level detection simulation oil well,to collect the echo signal,and to analyze domain characteristics of the detection signal,and to determine the signal processing requirements for the dynamic level detection.On the hardware,with the STM32 microcontroller as the core,the signal processing circuit of the oil well dynamic level detection consists of filter circuit,A/D analog-digital conversion circuit,RS-485 data transmission circuit;In software,the FIR digital filter designed by the window function method is used to filter noise and the eigenvalues of the hoop signal and the liquid level signal are extracted by using FFT and wavelet transform.The extracted eigenvalues are used to calculate the sound speed and depth of dynamic liquid level of the oil well,and the processing interface of the oil well dynamic liquid level signal is designed to display result of signal processing.The subject describes the processing result of signal form dynamic liquid level detection simulation wells and analyzing the processing results' effect and error.Finally,it is applied in actual wells to verify that the oil well dynamic liquid level detection signal processing technology is feasible.The actual application results show that the processing technology of the oil well dynamic level detection signal achieves denoising,the extraction of feature values,the calculation of the dynamic liquid level depth,the signal waveform after noise reduction processing is smooth,and the detection signal features are more easily extracted.The calculation error of the oil well dynamic liquid level is less than 1.00%.The research has certain popularization value for the accurate calculation of the oil well dynamic liquid level signal.