A poroacoustic Biot medium is used very often as the admissibleapproximation for a real oil-filled collector. For such a medium theshear stress of the matrix is equal to zero. In infinite poroacousticspace only fast P-waves and slow P-waves propagate with velocities ν1 and ν2. The fast wave resulting from thesolid and fluid parts moving in phase is similar to the ordinarycompressional wave. The slow wave which is the consequence of the solidand fluid part moving out of phase attenuates very rapidly and thereforecan not be observed at long distances. Earlier we have shown that aninterference slow wave exists in the poroacoustic layer located insidethe elastic medium. This wave has very low frequency and velocity andhigh amplitude. Here we show that in this model a new guided wave existswhich has a number of unusual peculiarities
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