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Weatherford's Downhole Optical Cable
Quick Links to Information Below
- Overview of the Downhole Optical Cable
- Applications for the Downhole Optical Cable
- Downhole Optical Cable Features, Advantages, and Benefits
- Options of the Downhole Optical Cable
- Specifications of the Downhole Optical Cable
PDF Documents
Overview of the Downhole Optical Cable
Weatherford's downhole optical cable provides a reliable, high-performance optical pathway for transmission of signals to in-well optical sensing systems such as pressure, temperature, flow, phase-fraction, distributed-temperature-sensing (DTS), and seismic systems.
The standard cable consists of two single-mode fibers for pressure gauges, flowmeters, and seismic systems and one multimode fiber for DTS systems. Pressure gauges and seismic stations are multiplexed on a single fiber, while a downhole cable splitter can be used to further enable multi-zone sensing architectures that deliver enhanced production monitoring capabilities.
The cable is engineered for reliable high performance throughout the life of the well. Weatherford's proprietary design incorporates a proven fiber-protection system that prevents the optical fibers from degrading over time, eliminating the need for periodic replacement. In addition, the fiber-protection system ensures that the factory calibration of the multi-mode fiber—used for DTS measurements—is maintained over the life of the well.
Applications for the Downhole Optical Cable
Weatherford's downhole optical cable is used in downhole optical sensing applications, including reservoir pressure and temperature, DTS, flow, and phase-fraction sensing.
Downhole Optical Cable Features, Advantages, and Benefits
- Non-electrical design is intrinsically safe.
- In the event of accidental damage, cable can be repaired at the well site, minimizing interruptions in operation.
- Loose-tube design isolates and protects fibers from cable stresses. This feature, coupled with industry-leading fiber protection, ensures reliability throughout the life of the well.
- A standard, integrated system of dry- and wet-mate connectors enables the cable to pass readily through wellheads, packers, safety valves, and other in-well equipment.
- Cable packaging is identical to that of other in-well hydraulic and instrument lines, allowing use of standard handling and installation techniques.
- The cable complies with industry standards for instrumentation cable.
Options of the Downhole Optical Cable
- Two sizes are available: 1/4 and 1/8 in.
- A choice of final encapsulation material is available. The cable can be packaged as part of a flat pack with other instrumentation and control lines to simplify rig-site deployment.
- Various cross-coupling clamping options are available.
- Custom optical fiber configurations can include any combination of single-mode and multi-mode optical fibers to meet application requirements.
Specifications of the Downhole Optical Cable
Typical Encapsulation Options |
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Material |
Maximum Temperature Rating |
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°F |
°C |
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Polyamide |
200 |
90 |
Polyolefin copolymer |
210 |
100 |
Heat-stabilized polyolefin copolymer |
240 |
115 |
EPDM/propylene copolymer |
260 |
130 |
Polyvinylidene fluoride |
280 |
140 |
ETFE |
310 |
155 |
Teflon ® FEP |
400 |
205 |
Teflon PFA |
500 |
260 |
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1/8-in. Cable |
1/4-in. Cable |
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0.028-in. Wall |
0.035-in. Wall |
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Construction |
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Optical fibers |
2 single-mode, 1 multi-mode |
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Inner metal tube |
304 stainless steel |
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Buffer |
N/A |
Teflon® |
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Outer armor tube |
316 SS or INCOLOY® 825 0.125-in. OD x 0.022-in. wall |
INCOLOY 825 0.250-in. OD x 0.028-in. wall |
INCOLOY 825 0.250-in. OD x 0.035-in. wall |
Mechanical Properties |
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Weight (in air) (lb/ft) |
0.03 |
0.1 |
0.11 |
Working pressure (PSI/ bar) |
20,000 (1,379) |
20,000 (1,379) |
25,000 (1,724) |
Collapse pressure (PSI/ bar) |
>30,000 (2,068) |
>30,000 (2,068) |
>35,000 (2,413) |
Burst pressure (PSI/ bar) |
34,000 (2,344) |
20,000 (1,379) |
25,000 (1,724) |
Maximum tensile load (lb/ kg) |
500 (227) |
1,500 (680) |
2,000 (907) |
Maximum splice-free length (ft/ m) |
20,000 (6,096) |
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Minimum bend radius >1 turn (in./ mm) |
2 (50.8) |
4 (101.6) |
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Minimum bend radius <1/2 turn (in./ mm) |
1 (25.4) |
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Environmental Specifications |
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Operating temperature range (°F/ °C ) |
32 to 230 (0 to 110) |
32 to 302 (0 to 150) |
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Storage temperature range (°F/ °C ) |
–40 to 230 (–40 to +110) |
–40 to 302 (–40 to +150) |
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Pressure range (PSI/ bar ) |
Atmosphere to 20,000 (1,379) |
Atmosphere to 20,000 (1,379) |
Atmosphere to 25,000 (1,724) |
Teflon is a registered trademark of DuPont. INCOLOY is a registered trademark of the Special Metals Corporation group of companies.
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Copyright © 2007 eProduction Solutions, Incorporated. All rights reserved. |
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