摘要
本文研究了低速地层裸眼井中由点状声源激发的弹性波的传播问题,指出,井中存在着沿井轴方向分别以地层中纵波速度v_c和横波速度v_3传播的无频散几何衰减波,且当v_(?)<(1-ρ_1/ρ_2v_1)^(1/2)时,二者具有各自的传播特征频率,当v_(?)>(1-ρ_1/ρ_2v_1)^(1/2)时,几何衰减横波无传播特征频率;斯通利波的截止频率为远场处横渡的传播特征频率,该频率处斯通利波的相速度等于地层中横波传播速度;低速地层裸眼井中无泥浆直达波。
In this paper, the propagation of the elastic wave excited by the point acoustic source in the uncased hole of low velocity formation was examined. Jt has been pointed out that there exists the undispersed geometric attenuation wave in the hole which propagated along the hole axis with the P-wave Vc and the S-
wave V, of the formation. While ν, each of them has its characteristic frequency of propagation. And
while ν, > ,no charateristic frequency can be found from the geometric attenuation S-wave,the phase - velocity of the Stoneley wave is equal to the S-wave velocity of the formation. There is no direct wave through the mud in the uncased hole with low velocity formation.
出处
《石油物探》
EI
CSCD
北大核心
1990年第4期59-66,46,共9页
Geophysical Prospecting For Petroleum
