Waveguide Acoustic Control of Pipes - Billets of Deep Rod Pumps

Abstract

Deep rod pumps are expensive maintenance-free equipment for extracting oil from wells. The exclusion of defective billet pipes from the technological cycle of manufacturing elements of such pumps significantly affects both the cost of their production and the cost of production. A waveguide method is proposed for continuous input testing of tube billets of rod pump cylinders. It does not require scanning and is highly sensitive to both internal and surface defects. An experimental assessment of the sensitivity of the method to defects in the form of an influx located on the outer and inner surfaces of a thick-walled pipe with a diameter of 59.3 mm and a wall thickness of 14 mm was carried out. The echo signal from the artificial reflector decreased by 2 dB when the reflector was moved from the outside of the pipe to the inside. The criteria for rejection of the blank pipe are determined by the signal level at the first reflection R1, at the 8th reflection RN and by the attenuation coefficient b. As a result of flaw detection of billet pipes, a pipe with a significant defect was found. An experimental study of the acoustic properties of a batch of pipes with a diameter of 58 mm in the delivery state was carried out. For the billets of the cylinder of the deep rod pump in the delivery state, the lower acceptance limit for the torsional wave velocity of 3255 m/s has been determined. The influence of technological operations of high tempering and straightening on their acoustic properties is estimated. The possibility of quality control when performing the release operation by the guided wave method is shown. It was revealed that during the tempering procedure, the velocity of the torsional wave increases, on average, by 27 m/s per batch.