An oil and gas pipeline detector based on the frequency mixing amplitude algorithm and its application

At present, an underground oil and gas pipeline detector consumes much power due to its high sampling rate and high precision. In order to solve this problem, the frequency mixing amplitude algorithm was put forward, so that the receivers of the detectors could perform sampling and calculate the buried depth of oil and gas pipelines even though the sampling frequency is far less than two times of the transmission frequency. It is indicated from the working principles of underground pipeline detectors that the measured signals are constant-amplitude sine signals. Frequency mixing signals are obtained when the measured signals and the square wave signals are mixed by using the multiplier. Then, the lower frequency signals are obtained by means of the low-pass filter circuit and the frequency is the frequency difference between the square wave signal and the sine signal. The burial depth of oil and gas pipelines can be confirmed when the receivers collect the low-frequency signals and calculate their intensity amplitude. It is shown from the experiments that the requirements on underground oil and gas pipeline detections are satisfied with the relative depth error less than ±2% and the induction voltage amplitude measured by the receivers is stable and reliable when the pipelines are buried above 2 m. And furthermore, the power consumption and cost of underground oil and gas pipeline detector are reduced significantly, and its performance-price ratio is improved greatly.