Method and apparatus for LWD shear velocity measurement
    1.
    发明公开
    Method and apparatus for LWD shear velocity measurement 有权
    用于测量LWD Sheargeschwindigkeit方法和装置

    公开(公告)号:EP1505411A3

    公开(公告)日:2007-12-19

    申请号:EP04024171.3

    申请日:2001-11-13

    IPC分类号: G01V1/44 G01V1/52 G01V1/28

    CPC分类号: G01V1/44

    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.

    Method and apparatus for LWD shear velocity measurement
    2.
    发明公开
    Method and apparatus for LWD shear velocity measurement 有权
    VERFAHREN UND VORRICHTUNG ZUR LWD- MESSUNG DER SHEARGESCHWINDIGKEIT

    公开(公告)号:EP1505411A2

    公开(公告)日:2005-02-09

    申请号:EP04024171.3

    申请日:2001-11-13

    IPC分类号: G01V1/44 G01V1/52 G01V1/28

    CPC分类号: G01V1/44

    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.

    摘要翻译: 本发明的测井工具(90)包括在钻铤上传送的发射器(105),用于激发由钻头钻的钻孔中的四极杆信号(106)和用于接收信号的接收器。 发射机的工作频率低于四极杆模式的截止频率。 所接收的信号主要由形成四极杆模式组成,其在低频时具有接近地层剪切速度的速度。 在一个实施例中,发射器由安装在钻铤的边缘上的压电圆柱体的八个相等的部分组成。 截止频率的值主要取决于钻铤的厚度。 或者,发射机可以被操作以产生领带模式和形成模式,并且处理器可以用于过滤衣领模式。