The Cable Orientation Beacon (COB) is an autonomous downhole sensor that is installed adjacent to the fibre optic cable (FOC) under a standard mid-joint clamp.
Fibre optic cables installed on the outside of completion casing are at risk of being damaged during perforation. To avoid damaging the FOC the perforation charges are oriented away from the FOC. In order to do this, the orientation of the FOC must be determined when the installation is complete.
Unlike traditional sensors that use wireline electromagnetic or ultrasonic tools inside the casing to detect the presence of the cable on the outside of casing, Silixa’s COB measures its own orientation using an internal sensor, then transmits that data to the FOC via an acoustic signal to be detected by iDAS™.
The acoustic signal is read at surface and translated back to an orientation in the form of an angular position around the outside of the casing relative to the high side of the borehole