Auniontech AUT-F100 Downhole Distributed Fiber Optic Sensing System for Oil & Gas Wells

Overview

The Auniontech AUT-F100 is a purpose-engineered downhole distributed fiber optic sensing system designed for permanent or semi-permanent installation in oil and gas wells. It leverages coherent optical time-domain reflectometry (C-OTDR) and Brillouin optical time-domain analysis (BOTDA) principles to deliver continuous, real-time, spatially resolved measurements of temperature (DTS), acoustic vibration (DAS), and strain along the entire length of a single-mode optical fiber deployed within the wellbore. Unlike point-sensor arrays, the AUT-F100 transforms the well’s optical cable into a dense, kilometer-scale sensor array—enabling full-well profiling without mechanical intervention. Its architecture supports high-temperature, high-pressure (HTHP) environments typical of deep reservoirs and unconventional plays, with validated operation up to 150 °C and 10,000 psi. The system is engineered for long-term stability in corrosive downhole fluids and mechanically robust under dynamic tubing movement, cement sheath stress, and thermal cycling—making it suitable for both vertical, deviated, and horizontal completions.

Key Features

• True distributed sensing: Simultaneous DTS and DAS acquisition over a single fiber, eliminating need for multiplexed discrete sensors.
• High spatial fidelity: 1-meter resolution for temperature profiling; 10-meter resolution for acoustic event localization (e.g., sand production, fluid entry, valve actuation).
• Real-time monitoring capability: Up to 10 kHz sampling for transient acoustic events (e.g., microseismicity, flow regime transitions) and synchronized 1 Hz temperature logging.
• Integrated ruggedized interrogation unit: Designed for surface skid-mount deployment with IP65-rated enclosure, wide-input DC power range (12–36 V), and industrial-grade EMI shielding.
• Calibration traceability: Factory calibration performed against NIST-traceable reference cells; field recalibration supported via built-in reference sections and dual-end injection protocols.
• Interoperable hardware interface: RS485, Ethernet (TCP/IP), and Modbus TCP output for integration with SCADA, DCS, and digital twin platforms.

Sample Compatibility & Compliance

The AUT-F100 is compatible with standard ITU-T G.652.D and G.657.A1 single-mode fibers installed during well completion or retrofitted via slickline/cable-deployed fiber reels. It supports both bare fiber (for direct cement bond) and armored fiber cables (for protection in high-abrasion zones). The system complies with API RP 14E (design and installation of subsea production systems), IEC 61508 (functional safety for electrical/electronic/programmable electronic safety-related systems), and meets EMC requirements per EN 61000-6-2/6-4. Data integrity and audit readiness are ensured through optional 21 CFR Part 11-compliant software modules supporting electronic signatures, change history, and user access control—facilitating GLP/GMP-aligned operations in regulated upstream asset management workflows.

Software & Data Management

The AUT-F100 operates with Auniontech’s proprietary FOSView™ software suite, a Windows-based platform providing real-time visualization, multi-parameter overlay (e.g., DAS spectrograms overlaid on DTS profiles), automated event detection (sand ingress, water breakthrough, casing leak), and time-lapse reservoir modeling interfaces. Raw data is stored in HDF5 format with embedded metadata (GPS timestamp, fiber position mapping, laser wavelength, pulse width), ensuring FAIR (Findable, Accessible, Interoperable, Reusable) data principles. APIs (RESTful and OPC UA) enable bidirectional integration with reservoir simulators (e.g., Eclipse, CMG), historian systems (OSIsoft PI, AspenTech IP.21), and cloud analytics platforms (AWS IoT Greengrass, Azure Digital Twins). All software modules undergo annual third-party penetration testing and support TLS 1.2+ encryption for secure remote access.

Applications

• Reservoir surveillance: Continuous pressure gradient estimation via thermo-hydraulic coupling models; identification of compartmentalization and thief zones.
• Production optimization: Real-time flow regime classification (slug, annular, mist) in multiphase flow; quantification of liquid loading onset in gas wells.
• Well integrity monitoring: Detection of casing deformation, cement debonding, and microannulus formation via strain anomaly mapping.
• Sand management: Localization and rate estimation of sand production using high-frequency DAS spectral energy thresholds (>5 kHz band).
• Hydraulic fracturing diagnostics: Distributed microseismic source location and fracture growth tracking during stimulation.
• Enhanced oil recovery (EOR): Steam front progression monitoring in SAGD wells; CO₂ plume migration tracking in sequestration projects.

FAQ

Can the AUT-F100 be integrated with existing SCADA or WITSML infrastructure?

Yes—the system provides native Modbus TCP and WITSML 1.4.1 drivers, and supports custom protocol translation via its open API framework.

What fiber type and installation method is recommended for high-temperature wells?

We recommend polyimide-coated G.652.D fiber with stainless-steel armor and thermally stable buffer layers, installed using coiled-tubing-conveyed fiber reels or cemented behind casing.

Does the system support remote firmware updates and health diagnostics?

Yes—over-the-air (OTA) firmware upgrades and real-time laser health metrics (power drift, SNR degradation, coherence length) are accessible via encrypted SSH or web dashboard.

How is measurement accuracy verified in-field after installation?

Field validation is performed using known thermal references (e.g., calibrated downhole gauges at multiple depths) and cross-correlation with pulsed neutron logs; Auniontech provides traceable uncertainty budgets per ISO/IEC 17025.

Is the AUT-F100 certified for use in hazardous area classifications (e.g., ATEX, IECEx)?

The surface interrogation unit carries ATEX II 2G Ex db IIB T4 Gb certification; intrinsic safety barriers are required for downhole fiber termination boxes in Zone 1 environments.