摘要
利用相控线阵声源的动态声束偏转技术可大大增强套管井孔中有用模式波的幅度。通过实轴积分方法计算了相控线阵声源在多种胶结状况下的充液套管井中的声场,计算结果表明在Ⅰ、Ⅱ界面均胶结良好时随着相控线阵阵元间激励延迟时间的增加,地层滑行纵波和滑行横波的幅度逐渐增强,当相控线阵声源的声束偏转角先后等于地层第一临界角和第二临界角时可使滑行纵波和滑行横波幅度分别加强到最大;在Ⅰ(或Ⅱ)界面存在微环时,单个点声源激发的套管井全波波形中观测不到地层信息,当采用相控线阵声源做发射器时,通过选择相邻阵元间合适的激励延迟时间,可有效地增强地层滑行纵横波的幅度,同时还可较好的抑制套管波的能量。
The useful mode wave can be stimulated effectively by using of the linear phased-array transmitter with controllable beam steering characteristic. The synthetic acoustic waveforms excited by the linear phased-array transmitter in cased boreholes are calculated with various cement bonding cases for the two interfaces outside the steel casing. When the generation conditions of the refracted compressional wave and the refracted shear wave are reached successively by regulating the direction of acoustic beam radiated from the linear phased-array transmitter, the refracted compressional wave and the refracted shear wave are strengthened respectively with both good bonding interfaces. The refracted compressional wave and the refracted shear wave can be stimulated obviously and the casing wave can be suppressed effectively, even when the casing and cement（or the cement and formation） is not bonded. Contrastively the formation information can not be detected in the received full waveform excited by one point source.
出处
《声学学报》
EI
CSCD
北大核心
2007年第4期328-332,共5页
Acta Acustica
基金
国家自然科学基金重点资助项目(10534040)
国家自然科学基金面上资助项目(40574049)
