Research On Detection System Of Underwater Crossing Ultra-deep Pipeline

With the rapid development of China’s economy,the underground pipeline system is becoming increasingly huge.For the oil pipelines and the gas pipelines,many of them often need to pass through the rivers.In the pipeline engineering,two methods are often used,crossing and spanning.The way of crossing is to let the pipeline pass through the river from below the riverbed.Compared with the pipeline under the land,the natural environment of the pipeline under the riverbed is more complicated,and the pipeline is more prone to safety hazards.With the erosion of the river bed and the continuous change of the geological structure,the pipeline may be exposed to the riverbed.The direct contact with the river water causes corrosion and damage to the pipeline,and ultimately leads to oil and gas leakage.Therefore,after the underwater pipeline is constructed by directional drilling,the pipeline needs to be inspected regularly,in order to find out the specific position of the pipeline under the riverbed,and clarify the actual distance between the pipeline and the riverbed.The underwater pipeline can be inspected before oil and gas leakage occurs.Deal with the hidden danger in time.Firstly,this article introduces the law of radiating magnetic field from underwater crossing pipelines,the principle of pipeline detection using direct electromagnetic induction method.At the same time explain the specific circuit implementation plan,mainly for the purpose of generating,receiving,and measuring electromagnetic signals,design the detection circuit,complete the research and development of underwater ultra deep pipeline detection equipment.At the same time,the software program control method of MCU in the circuit is introduced.This research is based on the necessary theoretical analysis,supplemented by the simulation of the corresponding circuit,and finally realizes the specific circuit function.The difficulty of the design of this research is to realize the effective acquisition and extraction of large-scale weak signals under the premise of meeting the measurement accuracy,how to improve the signal-to-noise ratio of the circuit and the anti-interference ability of the entire system.This article first gives the overall block diagram of the system,the circuit block diagram of the transmitting system,and the circuit frame of the receiving system.The specific functions and detailed design implementation methods of each functional module are described in detail in sub-systems and sub-sections.The circuit schematic diagram,simulation results and physical circuit diagram are also given.The main purpose of this research is to use electromagnetic induction to accurately measure the buried depth of the pipeline.In order to ensure the accuracy of the measurement and the anti-interference ability of the system,the receiver system adopts the design of digital filter,and the control chip adopts MSP430+FPGA multi-core structure.Subsequently,this article gives the program design flow chart of MSP430 and corresponding control methods in subsections,and then briefly introduces digital phase-sensitive detection and FPGA implementation of digital phase-sensitive detection methods.Finally,the modules of the transmitting system and the receiving system are tested to ensure the realization of the functions of each module.Simultaneously,a simulation test environment is built to complete the test of the system joint debugging.Finally,the on-site field test is carried out,through the actual detection of two river crossing pipelines.The actual pipeline inspection results are compared with the ONEPASS.The final test results show that: the system can realize the detection of the buried pipeline within 40 meters,the detection error is controlled within 5%,the performance of the instrument is stable and reliable,all functions can be realized,the detection system designed and developed in this subject can be used in engineering projects.