Research The Method Of A Non-contact Ultrasonic Method For Caliper Logging

Ultrosonic measuring method is a wide used nondestructive examination measuring technic. Caliper logging is belonged to engineering well logging; its target is to measure the diameter of casing or tubing.This subject emphasizes on the how to meature the factual runner's diameter which the pipe wall is attached the fouling and the stain thickness by non-contact ultrasonic method in complex fluid environment in injection profile. At first, an analysis on the purpose and significance of caliper logging has been given, as well as the principles of caliper logging by ultrasonic and the propagation characteristics of ultrasonic all has been given. Secondly, all influencing factors of ultrasonic measuring method are countered, the paper has maken an intensive study of principles and performance of ultrasonic transmitting probe, and the design of hardware circuit. A high precision of ultrasonic Time Difference method and how to realize it by MATLAB also have been introduced. At last, based on all fundamental researches, there is an experiment has been carry out for ultrasonic measure method. The pipe wall sockets depth and lubricate stain thickness are measured in the experiment. We can know all kinds of experiment media's acoustic impedance properties from the interpretation of result. The results of experiment show us that: Ultrasonic can measure the depth of pipe wall sockets effectively under short distance. It also can measure a certain thickness of lubricate stain effectively. The received echo wave's amplitude is keeping with the theoretical sound pressure value. So the result of experiment is credibly.The significance of study on the subject is to develop a non-contact mode method of caliper logging. Ultrasonic measurement mode has many merits such as low power, non-contact and continuous measurement. It can measure the variant of bore for perforation, corrosion, paraffin, contamination and so on in injection profile. Study on the subject is to form an available theory that can be used on measuring fluid flow passage in well and to provide theory considerations and experiments considerations for developing related instruments. At present, mechanical, electromagnetic and laser caliper logging tools all can not measure the variant of bore for contamination effectively. While ultrasonic measure method can overcome the deficiencies of other methods. It can be used to achieve the correct measurement of hole diameter, and achieve the correct measurement of flow rate. It wil be widely used.