Cable Mapping

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.

Prevents cable damage at perforation

Accurately mapping the orientation of downhole optical sensing cables enables operators to avoid cable damage at perforation.

Significantly reduced overall costs

COB is an autonomous sensor installed under a standard mid-joint clamp. As no additional hardware is required, it is easy to install on the casing . This not only eliminates the need for tractored or wireline services, but makes running casing easier and improves chances of a successful cement job. The overall costs are hence reduced.

Flexible installation

COB can be installed under a variety of cable clamp types.

Provides downhole depth calibration points for iDAS

Since the COBs are installed inside the completions string they can be used to calibrate the extra fibre length inside fibre optic cables to known reference depths downhole.