Silixa’s cable mapping service is a cost-effective, low-risk solution for mapping the orientation of downhole optical sensing cables in order to avoid cable damage at perforation.

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.

Specifications

Parameter Cable Orientation Beacon
Housing length 10 inch
Housing diameter 7/8 inch
Pressure rating 10kpsi
Temperature rating 150°C
Angle resolution 10°

Key benefits

  • Reduces overall costs by eliminating the need for tractored wireline services
  • Can be installed under a variety of cable clamp types
  • Eliminates the need for additional hardware on the casing reducing the cost of fibre installation
  • Reduced hardware makes running casing easier and improves chances of a successful cement job
  • Provides downhole depth calibration points for the iDAS

COB is an autonomous downhole sensor that is installed adjacent to the fibre optic cable under a standard mid-joint clamp.