| Memory-type downhole visual detector is based on the photoelectric camera and circuit control system assembly,combined with mechanical structure,to achieve the protection of the outside of the detector.With the late development of the major oil fields,the workover well and sidetracking well is increasing,the current workover operations are using impression block method of detecting the fish and the shape of casing,but they can not determine the detail of downhole,especially the highly deviated wells and horizontal wells.Memory-type downhole visual detector can effectively solve the above problems.This paper analyzes and studies the downhole visual detector based on the visible light source,and selects the high-definition,high-temperature industrial camera and the long working-time,high-temperature battery.An electronic circuit control system which meets the underground TV is designed and developed.An len sealing device which can meet the high pressure and high temperature and a set of fish top retreat mechanical protection tube are developed,effectively protecting the glass window of the Memory-type downhole visual detector.This paper uses the optical imaging principle,the camera lens are installed in the front of the instrument.When the detector is testing,the downhole camera lens is illuminated by the visible light source,and the inner wall of the well pipe is photographed.The image signal is generated through the processing of the electronic circuit,and the frequency pulse signal is generated,through the cable to the ground receiver,and decoded to form images.And through the analysis of the image,the real-time monitoring of casing condition is realized. |
