A multilayer medium model,incorporating drilling fluid,casing and cement,was established to study the response characteristics of flexural Lamb wave logging through theoretical calculations and experimental measurements.The theoretical simulations reveal that the dispersion curve of the flexural Lamb wave splits into two branches:a low-frequency branch and a high-frequency branch when the cement P-wave velocity intersects the dispersion curves of flexural wave within the logging frequency band.The direct flexural Lamb wave received also shows two compact wave packets.Experimental results further confirm this discontinuity in the dispersion curve,with the experimentally extracted curve aligning closely with analytical cal-culations.This phenomenon allows for direct determination of the cement̍s P-wave velocity from the breakpoint of the disper-sion curve,facilitating the identification of post-coupling cement types.
关键词
弯曲型Lamb波/频散曲线/衰减曲线/断点
Key words
flexural Lamb wave/dispersion curve/attenuation curve/break point
维普
万方数据