Ultrasonic Drilling Diameter Measuring Instrument Design And Achievement Of Simulation And System Control

In recent decades, in order to solve the logging in deviated wells, horizontal wells, and accurately obtain the original formation information, timely guide drilling work logging while drilling technology has been more and more used in oil and gas exploration and development,. In LWD many logging parameters, borehole information is an important decision parameters. But in the bad environment of high temperature and high pressure, mud circulation and drill pipe rotation,measurement of the diameter of well is always a problem. Therefore drilling diameter measurement is listed as the "Twelfth Five Year" major national science and technology projects, researching and developing while drilling diameter detection instrument is of great significance in engineering.According to the principle of ultrasonic ranging, using the non-contact, no damage, accurate and real-time characteristic, proposed ultrasonic drilling diameter measurement scheme, and experimental study was carried out, the two aspects of theory and experiments show the feasibility of the method. On this basis, puts forward the design scheme of the instrument, developed and impleted simulation and control, test results show that the functions of simulation and control meet the design requirements. The whole system debugging get through test of high temperature, high pressure and vibration,and obtain high quality logging data in the experiment well, finished scheduled tasks of design and research and development.The main innovation of this paper:①proposed new scheme of the ultrasonic drilling diameter measurement " wavelet excited correlation detection", solves the problems of conventional ultrasound reflection logging using threshold detection time echo method reaches the noise and echo amplitude high impact problem based on;②designed and implemented ultrasonic transmitting circuit based on CMOS switch, which solve high power consumption of the conventional single pulse excitation circuit, large volume, frequency offset problem of high temperature and high pressure;③designend and realized the voltage controlled gain amplifier, amplified the echo signal, compensated attenuation of ultrasonic in mud, improved the accuracy of echo arrival time detection.The research work of this paper is to solve the key technical problems of ultrasonic drilling diameter detection, have important practical engineering value.