Automated Ultrasonic Testing Method And System For Thickening Area Of Drill Pipe

Thickening area is critical area of drill pipe, because of tough and complex service environment, flaws such as holes,wall erosion and crack often occurred in this area, causing severe drilling accident. In order to improve drill pipe's service life and minimize the loss caused by flaws, automated test of thickening area of in-service drill pipe actually makes great sense.Considering several methods used in testing drill pipe's thickening area, immersion ultrasonic testing method, which is convenient for automated inspection, was chosen. Complexity of automated ultrasonic test of this area was analyzed and researched, which lay in inconsistency of parameters such as incidence angle, water path, etc. in different positions, thickening area's vibration caused by drill pipe's rotation, consistent comparison and quantitative analysis of different regional flaws, product differentiation, accordingly, regional, tracking, wall-thickness homogenization methods, which were available for automated test of different types of drill pipes, were proposed. In the system design, the motion that ultrasonic sensor array moves straight with drill pipe rotating was chosen. By theoretical computation, key test parameters such as incidence angle, water path and etc. were approximately made. Technical process and parameters of automated ultrasonic test were introduced. Through ultrasonic testing experiment on thickening area, immersion test was used, parameters such as incidence direction, angle, and etc. were optimized.Automatic ultrasonic testing system for in-service drill pipe's thickening area was designed and manufactured. Oblique incidence, transverse wave, and pulse-echo technique were adopted for test. Key sensor parameters such as type, frequency, crystal plate's size, focal length and etc. were determined. Several testing channels were set to separately test different regions. Mechanical actuating, automatic control,water recycling and other auxiliary parts for the system were designed. As practice proved, the system worked effectively, stably and precisely for automated ultrasonic inspection of in-service drill pipe's thickening area, and made good application effect.