定向扫描成像测井技术及其应用

Technique of Well Logging by Directional Scanning Image and Its Application

定向扫描成像测井技术,就是按照规定的方向对井壁进行扫描,把井壁展开成一个连续的平面。这种信号不能在磁屏蔽、磁干扰条件下工作,进而不能确定地质信息的方位。然而,当运用陀螺定向技术对人造磁场进行定向,在人造磁场中,转动的线圈感应出来的交变电信号作为图像扫描触发信号,能够测量所形成的超声图像,并快捷、准确地查明井管故障点的位置、损坏的规模大小和方位,从而为维修方案的确定提供了可靠的依据。

Technique of well logging by directional scanning image means scanning the wall of a well according to the given direction, and makes the wail of a well be unfolded to a continuous plane. Common ultrasonic imaging well logging instruments make the strongest magnetic north signal of terrestrial magnetic field as the starting point of scanning trigger signal, which can neither work in the condition of magnetic shielding or magnetic interference, nor ascertain the location of geologic information. However, by taking gyro-positioning technique to locate artificial magnetic field, the ultrasound image produeed by measurement processing, where AC （Alternating Current） signal is induced by rotated coils in the artificial magnetic field as the triggering signal for image scanning, we can quickly and accurately ascertain the fault spot and the damage scale and location of well pipes, so as to provide the reliable basis for making maintenance plan.