发明名称 |
Method and apparatus for LWD shear velocity measurement |
摘要 |
The logging tool of this invention includes a transmitter conveyed on a drilling collar for exciting a quadrupole signal 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 |
US2005078555(A1) |
申请公布日期 |
2005.04.14 |
申请号 |
US20040958221 |
申请日期 |
2004.10.04 |
申请人 |
BAKER HUGHES INCORPORATED |
发明人 |
TANG XIAO MING;PATTERSON DOUGLAS J.;WANG TSILI;LEGGETT JAMES V.;DUBINKSY VLADIMIR |
分类号 |
E21B47/14;E02D1/00;G01V;G01V1/00;G01V1/40;G01V1/44;(IPC1-7):G01V1/40 |
主分类号 |
E21B47/14 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|