发明名称 |
Method and apparatus for LWD shear velocity measurement |
摘要 |
The logging tool (90) of this invention includes a transmitter (105) conveyed on a drilling collar for exciting a quadrupole signal (106) in a borehole being drilled by a drill bit and a receiver for receiving the signal. The transmitter is operated at a frequency below the cut-off frequency of the quadrupole collar mode. The received signal consists primarily of the formation quadrupole mode which, at low frequencies, has a velocity that approaches the formation shear velocity. The transmitter, in one embodiment, consists of eight equal sectors of a piezoelectric cylinder mounted on the rim of the drilling collar. The value of the cut- off frequency is primarily dependent on the thickness of the drilling collar. Alternatively, the transmitter may be operated to produce both the collar mode and the formation mode and a processor may be used to filter out the collar mode. |
申请公布号 |
EP1505411(A3) |
申请公布日期 |
2007.12.19 |
申请号 |
EP20040024171 |
申请日期 |
2001.11.13 |
申请人 |
BAKER HUGHES INCORPORATED |
发明人 |
TANG, XIAO MING;PATTERSON, DOUGLAS;WANG, TSILI;LEGGETT, JAMES V. III;DUBINSKY, VLADIMIR |
分类号 |
E21B47/14;G01V1/44;E02D1/00;G01V1/00;G01V1/28;G01V1/40;G01V1/52 |
主分类号 |
E21B47/14 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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