Penetration power of ultrasonic guided waves for piping and well casing integrity analysis
Open Access
Author:
Parayitham, Sashidhar K
Graduate Program:
Engineering Mechanics
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
None
Committee Members:
Clifford Jesse Lissenden Iii, Thesis Advisor/Co-Advisor
Keywords:
well casing pipes guided waves excitation methods
Abstract:
Point source mechanical excitation methods are evaluated for the penetration power of the ultrasonic guided waves that they generate. An automatic center punch is selected for use in laboratory and field experiments because of the repeatable, large amplitude ultrasonic wave it generates. Laboratory experiments are conducted to investigate the effect of a threaded coupling and various realistic lateral boundary conditions on penetration power. A novel through-transmission technique using a down-hole fixture with two contact shear sensors is developed to study the mechanical integrity of steel casing for gas wells. Wave propagation is initiated at the top of the well through mechanical impact, which propagates flexural and torsional wave modes. The penetration power of ultrasonic guided waves using mechanical impacts is significantly larger than that of conventional piezoelectric elements. Different types of mechanical impacts, which vary in energy and in frequency are reviewed. Additionally, a shear transducer ring with high voltage excitation, used in pulse-echo mode, is also investigated.
The design of the down-hole fixture has the potential to be developed into a commercial well casing inspection device.
