Logging Cable Termination Sub

The logging cable termination sub provides a method of securing the cable and inhibits the ingress of fluids into the logging cable during normal coiled tubing operations.


The logging cable termination sub enables the operator to use logging coiled tubing for conventional runs without the added expense of providing two types of coiled tubing on the rig when both logging and manipulation work are required.

Fitting Method
The coil should be cut back to allow sufficient cable length protruding below to reach the position in the bottomhole assembly (BHA) at which the logging termination sub will be positioned.

After securing the coiled tubing connector and the upper part of the BHA to the coil, the logging cable is secured into the cable anchor, which is retained with shear pins into a shear sub. The shear pins allow the cable to release from its mounting if the logging cable encounters a tensile strain greater than the shear value of the shear pins.

The remaining cable is inserted into a termination body with a rubber element. The rubber element is compressed around the cable and into the bore of the body, and a suitable fluid repellent can then be injected through a nipple at the bottom of the body.

The outer sleeve is secured around the cable anchor and termination body to the top sub, and the bottom sub is then fitted to complete the assembly.

The remaining components of the BHA, which normally include a twin flapper check valve and overpressure shear sub release joint, can then be attached.

When ordering logging cable termination subs, please specify size/nipple and thread connection.

  • TerraTECH Coiled Tubing Tools Brochure

  • TerraLINK Coiled Tubing Connectors Data Summary