- Completion Tools
- SSDs
- Matrix Low Friction Centralisers
- Mechanical Drillpipe Swivel
- Turbine Reaming Solutions - Final String
- Target Depth Tech
- Expandable Casing Repair
- CX-2 Bridge Plug
- CX-10 Retrievable Bridge Plug
- CX-Enviroplug Rev 1
- CX-SV (Sliding Valve) Cement Retainer
- CX-SVE
- CX-Tubing Hanger
- CX- LTTT (HD) Liner Top Test Tool
- CX-RTP (Retrievable Test Packer)
- Cleanup Tools
- Cementing Equipment
- Cement Wash Equipment
- Drilling Equipment
- Intervention tools
- P&A Decommissioning
- Plug and Abandonment
- Renewable Energy
- Sealing Technology
- Subsea
- Well Integrity
- Reline Casing Repair
- Well Profiting and Monitoring
WELL-SENSE. June 2021
Well-SENSE FiberLine Intervention
Disposable Fibre Optic Intervention System for: Well Integrity Leak Detection, Pre-Abandonment Leak Detection Barrier Placement Verification
A new line in intervention
FiberLine Intervention (“FLI”)
Well surveillance and diagnostics at the speed of light
What is FLI
- A compact plug and play intervention system
- Laying bare optical fibre deployed from surface to total depth
- Combining either or both DTS and DAS – distributed temperature & acoustic sensing
- And single-point electronic sensors
- In real-time, delivering high-quality data
DTS Data Interrogation
DTS logs the data to an array table - CSV, DLIS, LAS etc.
- For each sample it records:
Time stamp (every 1 second to multi-hour user defined)
Temperature at every measurement point (gauge length user defined)
Stokes and Anti-Stokes at each measurement point
Loss Events (optical loss along the length of fibre)
- Interpretation Software solutions:
Can be imported into all commercial interpretation packages (Kappa, Plato etc.)
Thermal modelling can be applied to data sets
Data can be visualised in many ways
Absolute temperature, Delta temperature between points, Waterfall chart (heat map)
Used to determine fluid interface, cooling effects, flow characteristics, natural gradients, leaks
DAS Data Interrogation
When deployed in tubing a single DAS measurement can convey different information in different frequency bands:
- Low frequencies: 0-20hz (0-4hz = Strain Events)
Thermal disturbances
Fluid interfaces
Seismic (and micro-seismic)
- Medium frequencies: 2—100hz
Flow past obstacles
Behind tubing flow
- High Frequencies >100hz
Gas leaks
GLV flow
Tubing leaks
As you move away from the sound source, higher frequencies are attenuated quicker than lower frequencies. High frequency acoustic may only be detected some Centimetres from a sound source but low frequencies may travel for many metres. We use this to determine the point of flow origin.
FLI Single Point Measurements
- Single-point electronic sensor
- Pressure gradient measurement during RIH, and BHP
- Real-time, along fibre measurements
- Sensors can be included in the lower housing of a standard FLI Tool
When to use FLI: well lifecycle applications
Drilling
- Cement Assurance
- P/T Gradient
- Bottom Hole P/T
- Temperature
- Gradient/Profile
- Vertical Seismic
- Profile (VSP)
- Micro-seismic
- Monitoring
- Cross-well Strain
Completion
- Assess Completion Effectiveness
- Micro-seismic Monitoring
- Cross-well Strain
Production
- P/T Gradient
- Bottom hole P/T
- Temperature
- Gradient/Profile
- Acoustic Gradient/Profile
- Leak Detection
- Vertical Seismic Profile
Key Applications
Late Life
- P/T Gradient
- Bottom Hole P/T
- Temperature Gradient/Profile
- Injectivity Logging – Warm Back
- Acoustic Gradient/Profile
- Leak Detection
P&A
- Leak detection
- Cement Assurance/ Cement Plug Evaluation
- Pre Abandonment Thermal Profiling
Real Life Examples of Data Capture with FLI Cement Plug Verification & Pre Abandonment Leak Detection
FLI Leak Detection
- Date: 18/07/2020
- Application: DAS and DTS Leak Detection
- Well Status: Plugged
- Location: UK North Sea
FLI Objectives:
- Deploy tool into wellbore through the suspension flange
- Determine origin of sustained tubing pressure (GAS) cement plug passing OR compromised 9-5/8” Casing
- Remote monitoring of data acquisition – operational efficiency
Run In Hole Capture DAS and DTS
Cement Plug Leak Stimulation: First Bleed Down
Indication of Fluid movement from below the FLI originating from the Cement Plug.
Fluid movement observed to be repeatable, with multiple charge and discharge on A annulus
Cement Plug Leak Stimulation Summary
FLI was successfully landed out on the existing cement plug @ 4,935ft
A base line survey was logged before opening the A Ann to drain
Data was captured over 3 bleed down and charge cycles. Sufficient data was captured to identify leak location onsite
The data pointed to the cement plug passing. The cement plug was subsequently drilled out and replaced
FLI Leak Detection
- Date: 22/07/2020
- Application: DAS and DTS Leak Detection
- Well Status: Pre-Abandonment
- Location: UK North Sea
FLI Objectives:
- Deploy into completion tubing in between wireline operations for plug change out.
- Determine depth(s) at which gas is leaking into B-Annulus
- Remote monitoring of data acquisition
Barrier Placement Verification: Leak Stimulation First Pass
Barrier Placement Verification: First Pass Detail

Barrier Placement Verification Summary
- FLI was successfully deployed to target depth of 8,857ft and a base line survey was logged before opening the; Ann to drain through a ¼” line
- On opening the valve to drain, obvious and immediate acoustic event originating at a depth of 7,960ft observed
- The flow is observed to move upwards from this point to 7- 5/8” liner top, and downwards to a depth of 8,200ft which correlated to the top of milled window in the 9-5/8” casing
- No indication present of leak(s) originating above this area
Why FLI?
- Fit for purpose real-time intervention utilizing bare fiber
- Portable plug and play intervention system
- Rapid mobilization; minimal personal & logistics
- Cost effective / small footprint (1x FLI engineer)
- Low risk / health and safety priority
- Effective on and offshore
- Applicable in various applications
- No spool or fibre at surface (housed in tool / pays out on descent)
- Quality data
Or don’t FLI…
- Increased safety risk
- Increased POB
- Increased footprint
- Increase in timing / delay exposure
- Increased cost
- Data quality?