Monaco Well Logging Fiber Optic Cable Specifications

Well logging fiber optic cables are designed for harsh downhole environments, featuring robust mechanical protection, high-temperature resistance, and customizable fiber configurations for distributed sensing and telemetry.

Cable Construction

Well logging fiber optic cables typically use a tube-in-tube design, where the optical fibers are housed in a fiber-in-metal tube (FIMT) made of stainless steel or INCONEL® for hermetic sealing and chemical protection (SLB) . The FIMT can contain a mix of single-mode and multimode fibers to support distributed temperature sensing (DTS), distributed acoustic sensing (DAS), and distributed strain sensing (DSS) . Filling gels or solid foamed thermoplastic elastomers provide additional protection against microbending, moisture, and chemical ingress (TeleTechno) . The FIMT is supported within an outer tube by a polymer layer called the belt, which centralizes the fiber and provides mechanical buffering. The outer tube acts as the primary pressure barrier and mechanical shield, allowing the cable to withstand high pressures, elevated temperatures, mechanical shock, and corrosive fluids . Additional encapsulation or armor layers, such as corrugated steel tape or steel wire, enhance mechanical protection during deployment .

Mechanical and Thermal Specifications

• Temperature tolerance: Up to 150°C for traditional downhole cables, with high-temperature variants available for extreme wells .
• Pressure resistance: Designed to withstand extreme downhole pressures.
• Mechanical durability: Cables are engineered to endure repeated axial tension, bending, and spooling stresses during logging operations .
• Hydrogen resistance: Some designs incorporate hydrogen scavenging materials to prevent optical degradation in high-temperature wells .

Fiber and Sensing Capabilities

• Fiber types: Single-mode and multimode fibers for sensing and communication.
• Sensing applications: DTS, DAS, DSS, and telemetry to point sensors such as pressure and strain sensors .
• Deployment: Can be permanently installed behind casing or strapped to production tubing for continuous monitoring .

Customization Options

Well logging fiber optic cables are highly customizable to meet specific well requirements:

• Number and type of fibers
• Outer encapsulation and armor materials
• Filler materials and prestressing to minimize strain on fibers
• Metallic or dielectric designs depending on electrical isolation needs

Summary

Monaco well logging fiber optic cables, like other high-performance downhole cables, are engineered for long-term survivability in harsh environments, combining robust mechanical protection, high-temperature tolerance, and versatile fiber configurations. They enable real-time monitoring of temperature, acoustic signals, and strain, supporting enhanced reservoir management and well productivity. The design principles include tube-in-tube construction, fiber prestressing, and customizable armor and encapsulation, ensuring reliable operation throughout the well's lifecycle.