LNVESTIGATION ON THE PROPAGATION OF EMSTIC WAWS ALONG A FLUID-FILLED BOREHOLE IN SLOW FORMATION
Wang Xiuming;Li Zhanxian Department of Petroleum Prospecting
Further investigation on the propagation of elastic waves along a fluid-filled borehole in slow formation is studied in the paper. It is obtainedthat in this case, there exist the attenuated compressional waves andshear waves which have characteristic propagating frequencies respectively.Under the condition of v_s(1-ρ_1/ρ_2v_1)/2, there are no characteristicpropagating frequencics of the attenuated shear wave. It is also confirmedthat the phase velocity of Stoneley waves at the cut-off frequencies isequal to the shear velocity Vs. and no mud compressional wave exists.