Silixa’s ArrayLog™ service provides well integrity monitoring using existing fibres
Good well integrity is vital to eliminate the risk of uncontrolled release of formation fluids throughout the life of the well. Our ArrayLog™ services utilise distributed acoustic (iDAS™) and distributed temperature (ULTIMA™ DTS) data to detect fluid movement.
When well parameters point to the failure of a barrier it is necessary to identify the source of the failure in order to plan remediation, or to demonstrate the continued integrity of the barrier for normal operations. Distributed fibre optic sensing offers a unique way to quickly and efficiently detect the fluid movement which may indicate barrier failure.
The iDAS and ULTIMA DTS can be deployed periodically to detect leaks or flow behind casing by running a fibre optic log as either a slickline, cable or coil tubing intervention. The optical fibre behaves as a sensor array so the entire fibre path is surveyed simultaneously allowing well integrity issues at undetermined depths to be detected and localised almost immediately.
Where an optical fibre cable is pre-existing it is possible to interrogate the optical path without the need to intervene in the well.
- Rapid leak detection by scanning whole well with a single sensing array
- Real-time software enables rapid conclusions and optimises operating time
- Data acquisition on either slickline, cable or coiled tubing intervention
- Can be an intervention-less technique when using existing fibres
- Tubing to annulus communication detection
- Identify and confirm leaking completion components such as valves and plugs
- Detect fluid movement behind casing and track to origin
- Listen continuously for signs of cap rock failure during injection or disposal of CO2
With an optical fibre cable placed in an abandoned well, the iDAS was able to listen continuously over a period of several hours and subsequently capture a single discrete event signalling the periodic release of accumulated gas pressure behind casing. Unlike point sensor leak detection, the distributed nature of the iDAS measurement ensures that all such events are captured.