Elastomer seals and cement have been used for decades to seal the annulus between casings yet, as many field engineers will testify, these materials are known to have a high failure rate. Remediation using cement or resin squeezes leads to expensive, difficult and unreliable workovers.

Far from a one-tool-does-all solution, BiSN engineers have a developed Performance Barrier Technology platform to be specifically applied at the completions stage and adapted for annular sealing.

Ensure a competent annular seal at the beginning of a well’s life and eliminate the need for expensive interventions or unreliable cement squeezes in the future.
Reduce Gas Migration in the Annulus of New Wells with Wel-lok™ TDAP

The Wel-lok™ TDAP (Thermally Deformable Annular Packer) was developed as a preventative tool to be run as part of the original casing string.

How it works

Our unique eutectic alloy is placed in the well on the inner string during completion and cemented into place. After cementing the alloy is melted using a wireline-activated chemical reaction heater. With a viscosity similar to liquid water, the molten alloy fills the smallest of micro-annuli, leaving behind a seamless metal-to-metal seal.


  • Thermite element uses chemical reaction that is non-explosive, requiring no special licenses or handling permits
  • Can be deployed on any standard wireline without special connection
  • Density of eutectic alloy is 10 times that of water allowing it to displace wellbore fluids
  • Creates a V0 gas-tight seal in accordance with ISO 14310
  • Non-corrosive, environmentally-friendly material unaffected by H2S, CO2 or acid washes
  • Seal created in minutes and ready to test within one hour

View full technical sheet >>

Unique Alloys In Action

More than just a great idea, our Performance Barrier Technologies have been proven in the field time and time again.