Research on Monitoring Method of Cement Curing State Outside Steel Pipe Using Electromagnetic Ultrasonic SH Guided Waves

Steel pipe-cement（SC） cemented structure is widely used in industry, in which the cementing quality of SC can directly affect the service safety of the structure. Ultrasonic testing technology is the most important method to evaluate the cementing quality of SC. However, most of the current studies are devoted to the detection of cementing defects after cement curing, and pay less attention to the curing process which can directly affect the final quality of cement. On this basis, a method for monitoring the curing state of cement outside the steel pipe based on electromagnetic ultrasonic SH guided waves is proposed. This method relies on the sensitivity of SH guided waves to the shear characteristics of cement outside the steel pipe, and determines the shear characteristics of cement outside the steel pipe by measuring and calculating the attenuation of received signals' amplitude at different positions, so as to monitor its curing state. Firstly, the dispersion equation of the circumferential SH（CSH） guided