Surface Data Acquisition System Of Electromagnetic Defectoscope

In production process of the oil, gas or water well, the case-pipes have often been transfigured, damaged and corroded due to infection of the ambient conditions, thus, influencing the oilfield yields. It is quite necessary to find out the reasons of harming case-pipe, prevent the area of harmed case pipe from extending, confirm the project for maintaining the case-pipes and prolong the life of well by improving the scathed case-pipes inspections. Daqing oilfield studied and improved electromagnetic defectoscope recently which based on electromagnetic influence theory can detect the corrosion, transfiguration, fissure and thickness of the case-pipes in the well. At present, this technology has been already applied in Daqing oilfield and the result improved to be well. But the number of the imported surface data acquisition system is few and the failure rate is high can't satisfy the request of the oilfield .Finally, by analyzing received signal and doing a lot of experiments, we designed this system successfullyThe surface data acquisition system of electromagnetic defectoscope as a important part of the electromagnetic defectoscope application system is the power supply of the down hole instrument and the platform of the up logging signal's receiving, processing, decoding, coding and displaying. This paper introduces the design method, debugging process and the result of the field application.In the hardware part, the system makes use of the ripe MCU technology and adopts 8751 as the main controller which controls data acquisition, data processing, decoding, coding and signal's sending. By expanding signal regulation circuit, RS232 interface circuit and different kind of voltage regulators to finish the design of hardware part. The advantages of this structure are easily controlled and flexible expanded. In this structure, the powerful function of main controller can be used to simplify the circuit design in order to improve the reliability of the system.In the software part, the exertion of the host function and the integration of the software and hardware is the soul of the system design. These characteristic is considered when the system is designed, including interface friendly, efficiency and flexibility, complete combination, secondary development and convenient expandability. The software system programmed by Visual Basic 6.0 under a windows environment is composed by data acquisition software and play-back software. The data is received, displayed and stored by the data acquisition software and the data is replayed, processed and printed by the play-back software. The repeated experiment and field application indicate that this system which has many advantages such as stable capability, high accuracy, and high credibility, should satisfy the demand of electromagnetic defectoscope's expansion application and research experiment.